Nike, Inc. v. Adidas Ag ( 2016 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    NIKE, INC.,
    Appellant
    v.
    ADIDAS AG,
    Appellee
    ______________________
    2014-1719
    ______________________
    Appeal from the United States Patent and Trademark
    Office, Patent Trial and Appeal Board in No. IPR2013-
    00067.
    ______________________
    Decided: February 11, 2016
    ______________________
    MARK CHRISTOPHER FLEMING, Wilmer Cutler Picker-
    ing Hale and Dorr LLP, Boston, MA, argued for appellant.
    Also represented by WILLIAM F. LEE, KEVIN GOLDMAN;
    ANDREA WEISS JEFFRIES, Los Angeles, CA.
    MITCHELL G. STOCKWELL, Kilpatrick Townsend &
    Stockton LLP, Atlanta, GA, argued for appellee. Also
    represented by VAIBHAV P. KADABA, TIFFANY L. WILLIAMS.
    MICHAEL SUMNER FORMAN, Office of the Solicitor,
    United States Patent and Trademark Office, Alexandria,
    VA, argued for intervenor Michelle K. Lee. Also repre-
    2                                    NIKE, INC.   v. ADIDAS AG
    sented by NATHAN K. KELLEY, THOMAS W. KRAUSE, SCOTT
    WEIDENFELLER.
    ______________________
    Before CHEN, MAYER, and STOLL, Circuit Judges.
    CHEN, Circuit Judge
    This appeal arises from the inter partes review (IPR)
    of U.S. Patent No. 7,347,011 (the ’011 patent) owned by
    Nike, Inc. (Nike). The United States Patent and Trade-
    mark Office, Patent Trial and Appeal Board (Board)
    granted the IPR petition filed by adidas AG (Adidas) and
    instituted inter partes review of claims 1–46 of the ’011
    patent. Nike then filed a motion to amend in which it
    requested cancellation of claims 1–46 and proposed sub-
    stitute claims 47–50. The Board granted Nike’s motion to
    cancel claims 1–46, but denied the motion as to the sub-
    stitute claims because Nike failed to meet its burden of
    establishing patentability of substitute claims 47–50.
    Nike now appeals the Board’s denial of its motion to
    amend, and the Director of the United States Patent and
    Trademark Office (Director) intervened to defend the
    Board’s decision. For the reasons stated below, we affirm-
    in-part, vacate-in-part, and remand for further proceed-
    ings consistent with this opinion.
    BACKGROUND
    I
    Articles of footwear generally consist of two primary
    components: a sole structure and an “upper.” The ’011
    patent, entitled “Article of footwear having a textile
    upper,” relates to the “upper” component, which has the
    general shape of a foot and forms a void for receiving the
    foot that is accessed using the ankle opening. The upper
    disclosed in the ’011 patent is made from a knitted textile
    using any number of warp knitting or weft knitting
    processes. ’011 patent, 3:30–32. It is undisputed that
    NIKE, INC.   v. ADIDAS AG                                  3
    weft knitting is well known in the art and includes “flat
    knitting,” where the textile is knit as a sheet or flat piece
    of textile, and “circular knitting,” where the textile is
    produced as cylindrical textile structure. 
    Id. at 7:5–8,
    29–
    32.
    The knitted textile upper of the ’011 patent specifical-
    ly consists of “a single material element that is formed to
    exhibit a unitary (i.e., one-piece) construction” 
    Id. at 5:38–39.
    In another embodiment, this unitary textile
    element “may be formed as a part of a larger textile
    element” where the upper is then cut and “removed from
    the larger textile element.” 
    Id. at 5:43–45.
    Once manu-
    factured, the unitary textile element is then “formed or
    otherwise shaped to extend around the foot.” 
    Id. at 5:40–
    41. By manufacturing the upper component in this fash-
    ion, the “unitary construction is intended to express a
    configuration wherein portions of a textile element are not
    joined together by seams or other connections.” 
    Id. at 6:43–46.
    4                                    NIKE, INC.   v. ADIDAS AG
    Figure 8 of the ’011 patent illustrates the shape of the
    seamless unitary textile element before the various edges
    of the element are joined by seams in certain places to
    form the shape of the upper, as depicted in Figure 2.
    Nike’s proposed substitute claims generally relate to a
    unitary flat-knitted textile element:
    Claim 47. (Substitute for independent claim 16)
    An article of footwear comprising an upper incor-
    NIKE, INC.   v. ADIDAS AG                                  5
    porating a flat knit textile element, the flat knit
    textile element
    (1) having flat knit edges free of surrounding tex-
    tile structure such that the flat knit edges are not
    surrounded by textile structure from which the
    textile element must be removed, some of the flat
    knit edges joined together to form an ankle open-
    ing in the upper for receiving a foot, the ankle
    opening having an edge comprised of one of the
    flat knit edges; and
    (2) having a first area and a second area with a
    unitary construction, the first area being formed
    of a first stitch configuration, and the second area
    being formed of a second stitch configuration that
    is different from the first stitch configuration to
    impart varying properties to the textile element;
    and a sole structure secured to the upper.
    Joint Appendix (J.A.) 1226–27.
    II
    Adidas petitioned the Board for inter partes review of
    the ’011 patent, asserting that all forty-six claims were
    unpatentable under either 35 U.S.C. § 102 or § 103 in
    view of numerous prior art references. The Board granted
    review of certain of Adidas’s challenges to the patentabil-
    ity of all claims. After the Board issued its institution
    decision, Nike filed a motion to amend the claims in which
    it sought cancellation of claims 1–46 and proposed four
    substitute claims. In its final written decision, the Board
    granted Nike’s request to cancel claims 1–46. The Board
    denied, however, Nike’s request to enter substitute claims
    47–50 for two alternate reasons.         First, the Board
    acknowledged the requirement announced in the Board’s
    Idle Free decision that a patent owner “persuade the
    Board that the proposed substitute claim is patentable
    over the prior art of record, and over prior art not of
    6                                     NIKE, INC.   v. ADIDAS AG
    record but known to the patent owner.” J.A. 34–36.
    Because Nike’s motion included only a conclusory state-
    ment that the proposed claims were patentable over prior
    art not of record but known to Nike, the Board denied
    Nike’s motion. Alternatively, the Board denied entry of
    the substitute claims because Nike failed to establish that
    the substitute claims were patentable over the Nishida
    and Schuessler references.
    Nike filed a timely appeal from the Board’s decision,
    and the Director intervened. We have jurisdiction under
    28 U.S.C. § 1295(a)(4)(A).
    DISCUSSION
    We review the Board’s conclusions of law de novo and
    its findings of fact for substantial evidence. 5 U.S.C.
    § 706(2)(E); In re Sullivan, 
    498 F.3d 1345
    , 1350 (Fed. Cir.
    2007). “Substantial evidence is more than a mere scintil-
    la. It means such relevant evidence as a reasonable mind
    might accept as adequate to support a conclusion.” Con-
    sol. Edison Co. v. NLRB, 
    305 U.S. 197
    , 217 (1938).
    In this appeal, Nike raises three primary arguments.
    First, Nike asserts that the Board erroneously shifted to
    Nike (the patent owner) the burden of proving patentabil-
    ity of its proposed substitute claims 47–50. Second, Nike
    contests the Board’s finding on the merits that the pro-
    posed substitute claims are unpatentable as obvious.
    Finally, Nike objects to the Board’s practice of requiring a
    patent owner to establish patentability of substitute
    claims over all prior art known to the patent owner,
    including prior art not of record but known to the patent
    owner.
    I. Burden of Proof
    When Congress created IPR proceedings, it also en-
    acted 35 U.S.C. § 316, which directs the PTO to “prescribe
    regulations” governing a considerable number of different
    aspects of these new proceedings. 35 U.S.C. § 316(a).
    NIKE, INC.   v. ADIDAS AG                                   7
    Particularly relevant to this case is § 316(a)(9), in which
    Congress delegated authority to the PTO to prescribe
    regulations “setting forth standards and procedures for
    allowing the patent owner to move to amend the patent
    under [§ 316](d) to cancel a challenged claim or propose a
    reasonable number of substitute claims.” 
    Id. § 316(a)(9);
    see also 
    id. § 316(d)(1)
    (“During an inter partes review . . .
    , the patent owner may file 1 motion to amend the patent
    in 1 or more of the following ways: (A) Cancel any chal-
    lenged patent claim. (B) For each challenged claim,
    propose a reasonable number of substitute claims.”).
    Consistent with § 316(a)(9), the PTO promulgated a
    regulation relating to motions practice, 37 C.F.R. § 42.20,
    which explains that “[r]elief, other than a petition re-
    questing the institution of a trial, must be requested in
    the form of a motion” and that “[t]he moving party has the
    burden of proof to establish that it is entitled to the
    requested relief.” 37 C.F.R. § 42.20(a), (c).
    The Board addressed these regulations in its Idle Free
    “informative” decision in which it interpreted section
    42.20(c) and explained that “[t]he burden is not on the
    petitioner to show unpatentability [of new, substitute
    claims], but on the patent owner to show patentable
    distinction over the prior art.” Idle Free Sys., Inc. v.
    Bergstrom, IPR 2012-00027, 
    2013 WL 5947697
    , at *4
    (PTAB June 11, 2013); see also Patent Trial and Appeal
    Board, Standard Operating Procedure 2 (Revision 9), at 3
    (¶ IV.A–B) (Standard Operating Procedure 2), available
    at
    http://www.uspto.gov/sites/default/files/documents/sop2-
    revision-9-dated-9-22-2014.pdf (explaining that Board
    decisions labeled “informative” are “not binding authori-
    ty,” but provide “Board norms on recurring issues,” “guid-
    ance on issues of first impression,” and “guidance on
    Board rules and practices”).
    In our recent decision in Microsoft Corp. v. Proxyconn,
    Inc., we held that the Board’s interpretation of section
    8                                     NIKE, INC.   v. ADIDAS AG
    42.20(c) was permissible in light of the text of § 316(a)(9)
    and the language of the PTO’s regulation. 
    789 F.3d 1292
    ,
    1306–08 (Fed. Cir. 2015); see also 
    id. at 1307
    (“Nor can we
    say that the Board’s interpretation of § 42.20(c) in Idle
    Free—requiring the patentee to show patentable distinc-
    tion [of the substitute claims] over the prior art of rec-
    ord—is plainly erroneous or inconsistent with the
    regulation or governing statutes.” (alteration in original)
    (citation omitted)). We further explained that placing this
    burden on the patent owner for its newly formulated
    claims is appropriate given “the very nature of IPRs,”
    which are distinctly different from a typical PTO exami-
    nation or reexamination where a patent examiner per-
    forms a prior art search and independently conducts a
    patentability analysis of all claims, whether newly pro-
    posed or previously existing. 
    Id. at 1307.
        During IPRs, once the PTO grants a patentee’s
    motion to amend, the substituted claims are not
    subject to further examination. Moreover, the pe-
    titioner may choose not to challenge the patenta-
    bility of substitute claims if, for example, the
    amendments narrowed the claims such that the
    petitioner no longer faces a risk of infringement.
    If the patentee were not required to establish pa-
    tentability of substitute claims over the prior art
    of record, an amended patent could issue despite
    the PTO having before it prior art that under-
    mines patentability.
    
    Id. at 1307–08;
    see also 35 U.S.C. § 318(a) (instructing the
    Board to “issue a final written decision with respect to the
    patentability of any patent claim challenged by the peti-
    tioner and any new claim added under section 316(d)”).
    In this way, placing the burden on the patent owner
    ensures that proposed substitute claims are critically
    analyzed before they are entered as claims that are part
    of the issued patent.
    NIKE, INC.   v. ADIDAS AG                                 9
    Consistent with the language of the regulation and
    our subsequent conclusion in Proxyconn, the Board in the
    present case stated that Nike’s proposed substitute claims
    could not be “entered automatically,” but instead could be
    entered only “upon [Nike]’s having demonstrated the
    patentability of the substitute claims.” Adidas, 
    2014 WL 1713368
    , at *5. Ultimately, the Board denied Nike’s
    motion because it failed to carry this burden. Nike now
    argues that the understanding of the authority delegated
    in § 316(a)(9) from Idle Free and from Proxyconn is incor-
    rect in light of § 316(e):
    Evidentiary standards.—In an inter partes re-
    view instituted under this chapter, the petitioner
    shall have the burden of proving a proposition of
    unpatentability by a preponderance of the evi-
    dence.
    35 U.S.C. § 316(e) (emphasis added). On its face, § 316(e)
    places the burden of proving unpatentability on the
    petitioner as it relates to any patent claim included in the
    Board’s decision instituting the IPR proceedings. Nike
    interprets this provision as also placing on the petitioner
    the burden of proving unpatentability of any newly pro-
    posed substitute claim that the patent owner seeks to
    introduce during the proceedings. When § 316(e) is read
    in isolation, Nike’s position is not without some merit.
    But after considering the entire statute, we disagree that
    this section has such a broad command. See also Synop-
    sys Inc. v. Mentor Graphics Corp., No. 14-1516, slip op. at
    24–26 (Fed. Cir. Feb. 10, 2016).
    First, Nike’s interpretation is in tension with Con-
    gress’s direction that the PTO “shall prescribe regula-
    tions” “setting forth standards and procedures for
    allowing the patent owner to move to amend.” § 316(a)(9).
    In other words, Congress delegated to the PTO the specif-
    ic authority to establish the standards and procedures
    with which a patent owner must comply to amend its
    10                                    NIKE, INC.   v. ADIDAS AG
    patent during an IPR. Furthermore, the specific language
    in § 316(a)(9) also directs the PTO to set “standards and
    procedures . . . ensuring that any information submitted
    by the patent owner in support of any amendment en-
    tered under subsection (d) is made available to the pub-
    lic.” In this way, § 316(a)(9)’s requirement that the patent
    owner has some obligation to provide “information . . . in
    support of any amendment,” indicates that the patent
    owner carries an affirmative duty to justify why newly
    drafted claims—which, unlike the issued claims, had
    never been evaluated by the PTO—should be entered into
    the proceeding.
    This conclusion is further supported by inspection of
    the language of § 316(e). Specifically, the evidentiary
    standard set forth in § 316(e) applies to “an inter partes
    review instituted under this chapter,” making clear that
    the burden of proof is on the petitioner to prove unpatent-
    able those issued claims that were actually challenged in
    the petition for review and for which the Board instituted
    review. Synopsys, No. 14-1516, slip op. at 24–26; see also
    35 U.S.C. § 314(a) (authorizing IPR proceedings only
    when the information in a petition for review and any
    response “shows that there is a reasonable likelihood that
    the petitioner would prevail with respect to at least 1 of
    the claims challenged in the petition”). The evidentiary
    standard of § 316(e), when read together with § 316(a)(9),
    therefore does not necessarily apply to claims that were
    not in existence at the time a petition is filed, such as
    newly offered substitute claims proposed by a patent
    owner in a motion to amend filed as part of an already-
    instituted IPR proceeding.
    For these reasons, Nike’s attempt to undo our conclu-
    sion in Proxyconn—that the PTO may impose the burden
    of establishing the patentability of proposed substitute
    claims on the patent owner—is not persuasive. Nike’s
    argument focuses solely on a small portion of the lan-
    guage in § 316(e) and ignores the context supplied by the
    NIKE, INC.   v. ADIDAS AG                               11
    entirety of § 316. See Davis v. Mich. Dep’t of Treasury,
    
    489 U.S. 803
    , 809 (1989) (“[S]tatutory language cannot be
    construed in a vacuum. It is a fundamental canon of
    statutory construction that the words of a statute must be
    read in their context with a view to their place in the
    overall statutory scheme.”). Our precedent recognizes
    that § 316(a)(9) instructed the PTO to promulgate a
    regulation setting forth the standard for motions to
    amend a patent that might be filed as part of an IPR
    proceeding. The PTO did just that in 37 C.F.R. § 42.20(c)
    and, as we held in Proxyconn, the Board permissibly
    interpreted this regulation as imposing the burden of
    proving patentability of a proposed substitute claim on
    the movant: the patent owner. Section 316(e), on the
    other hand, speaks to a different context. Section 316(e)
    places the burden on the petitioner to prove unpatentabil-
    ity of any issued claim for which the Board has instituted
    review and requires that the petitioner carry this burden
    by a preponderance of the evidence. Thus, the Board did
    not err by placing the burden on Nike to establish patent-
    ability over the prior art of Nike’s proposed substitute
    claims.
    II. Obviousness
    Nike next asserts that the Board nevertheless erred
    in concluding that Nike failed to carry its burden of
    establishing that proposed substitute claims 47–50 were
    patentable under 35 U.S.C. § 103. Section 103 forbids
    issuance of a claim when “the differences between the
    subject matter sought to be patented and the prior art are
    such that the subject matter as a whole would have been
    obvious at the time the invention was made to a person
    having ordinary skill in the art.” 35 U.S.C. § 103. The
    ultimate determination of obviousness under § 103 is a
    question of law based on underlying factual findings. In
    re Baxter Int’l, Inc., 
    678 F.3d 1357
    , 1361 (Fed. Cir. 2012)
    (citing Graham v. John Deere Co., 
    383 U.S. 1
    , 17–18
    (1966)). These underlying factual considerations consist
    12                                      NIKE, INC.   v. ADIDAS AG
    of: (1) the “level of ordinary skill in the pertinent art,” (2)
    the “scope and content of the prior art,” (3) the “differ-
    ences between the prior art and the claims at issue,” and
    (4) “secondary considerations” of non-obviousness such as
    “commercial success, long-felt but unsolved needs, failure
    of others, etc.” KSR Int’l Co. v. Teleflex Inc., 
    550 U.S. 398
    ,
    406 (2007) (quoting 
    Graham, 383 U.S. at 17
    –18).
    A claimed invention may be obvious even when the
    prior art does not teach each claim limitation, so long as
    the record contains some reason why one of skill in the art
    would modify the prior art to obtain the claimed inven-
    tion. See Ormco Corp. v. Align Tech., Inc., 
    463 F.3d 1299
    ,
    1307 (Fed. Cir. 2006). Whether a person of ordinary skill
    in the art would have had such a reason to combine the
    teachings of prior art references is also a question of fact.
    Pregis Corp. v. Kappos, 
    700 F.3d 1348
    , 1353 (Fed. Cir.
    2012). Although an analysis of the teaching, suggestion,
    or motivation to combine elements from different prior art
    references is helpful, we must always be mindful that an
    obviousness inquiry requires an “expansive and flexible
    approach.” Kinetic Concepts, Inc. v. Smith & Nephew,
    Inc., 
    688 F.3d 1342
    , 1360 (Fed. Cir. 2012) (citing 
    KSR, 550 U.S. at 415
    , 419). Importantly, we have repeatedly em-
    phasized that an obviousness inquiry requires examina-
    tion of all four Graham factors and that an obviousness
    determination can be made only after consideration of
    each factor. 
    Id. On appeal,
    Nike objects to three components of the
    Board’s obviousness analysis. First, Nike contests the
    Board’s finding that a person of skill in the art would
    have a reason to combine the two relevant prior art
    references to arrive at the unitary upper claimed in the
    substitute claims. Second, Nike argues that the Board
    failed to consider Nike’s evidence of secondary considera-
    tions in violation of this court’s precedent. Finally, Nike
    contends that, at the very least, proposed claim 49 recites
    a limitation absent from the cited prior art references.
    NIKE, INC.   v. ADIDAS AG                               13
    A. Motivation to Combine
    In concluding that substitute claims 47–50 were un-
    patentable, 1 the Board pointed to three prior art refer-
    ences: (1) U.S. Patent No. 5,345,638 (Nishida), entitled
    “Process for producing a shoe-shaped part from a web of
    material and resulting shoe-shaped part”; (2) U.S. Patent
    No. 2,178,941 (Schuessler I), entitled “Knitted helmet”;
    and (3) U.S. Patent No. 2,150,730 (Schuessler II), entitled
    “Knitting machine.” In its Final Written Decision, the
    Board acknowledged that because Nike declined to file a
    response to the petition, the Board would “accept as
    unchallenged that Nishida teaches or suggests all of the
    limitations of [the] original claims.” Adidas, 
    2014 WL 1713368
    , at *18. This left only the added limitation in
    proposed substitute claims 47–50, namely, the recitation
    of “flat knit edges free of surrounding textile structure.”
    The Board found this limitation disclosed in Schuessler I
    and Schuessler II (collectively, the Schuessler Refer-
    ences). The Board then concluded that a person of skill in
    the art would have reason to modify Nishida using the
    teachings of the Schuessler References to arrive at the
    unitary, flat-knitted textile upper recited in the proposed
    substitute claims. Nike argues that this finding is not
    supported by substantial evidence. We disagree.
    1.
    As mentioned above, the Board’s obviousness conclu-
    sion rested on three prior art references: Nishida and the
    two Schuessler References.
    Nishida discloses a process that reduces the amount
    of waste produced when manufacturing shoe uppers.
    Nishida accomplishes this goal using a pattern where
    1  Nike does not argue claims 48–50 separately from
    claim 47 for the purposes of this argument.
    14                                     NIKE, INC.   v. ADIDAS AG
    only just those parts of the web of material are
    produced in the necessary quality, thickness, mul-
    tilayers or the like which correspond to the pat-
    tern or to an area of a pattern of the shoe upper or
    the related sole part. The remaining area of the
    web of material in contrast can consist of a simple
    lightweight or inexpensive material quality, which
    holds together only the patterns . . . .
    ’638 patent, 2:11–18. As shown in Figure 2 of Nishida,
    the textile corresponding to the pattern for the shoe upper
    is of a different quality or thickness than the remainder of
    the textile web.
    
    Id. at Figure
    2. The process disclosed in Nishida then
    requires that the portion of the pattern corresponding to
    the shoe upper be cut from the surrounding textile web.
    
    Id. at 2:20–22.
    After the upper is cut out, the “cutting
    NIKE, INC.   v. ADIDAS AG                               15
    waste” “represents a simple, lightweight and inexpensive
    material.” 
    Id. Nishida therefore
    improves on the prior
    art, where the cutting waste consisted of the normal, more
    “expensive tubular material, multilayer material or the
    like.” 
    Id. at 2:24–25.
         The Schuessler References both issued in 1939 to the
    same inventor. Schuessler I discloses “a method for
    forming a . . . knitted helmet while rendering it unneces-
    sary to cut any portion of the knitted swatch while at the
    same time providing a finished helmet,” ’941 patent, 1:16–
    19, rather than the traditional method of “form[ing] a
    knitted piece and then cut[ting] out portions and sew[ing]
    sections together to form the completed article,” 
    id. at 1:4–6.
    This manufacturing process allows the creation of
    the knitted article “in a continuous manner” “without
    requiring cutting.” 
    Id. at 1:24–26.
    Schuessler I further
    recognizes that this cutting-free method avoids the need
    for additional processing “to prevent unraveling” before
    the parts are sewn together. 
    Id. at 1:8.
    Schuessler I
    specifically references Schuessler II as an example of a
    knitting machine that can be used to form the knitted
    helmet disclosed in Schuessler I. See also Adidas, 
    2014 WL 1713368
    , at *19 (“The knitted helmet [of Schuessler I]
    may be formed from a swatch knit on a flat knitting
    machine, such as that described in Schuessler II.”).
    Schuessler II discloses a flat-knitting machine. ’730
    patent, 1:1–5. Thus, the flat-knitting machine can be
    used to manufacture the unitary textile element with flat-
    knit (not cut) edges that can be stitched in certain places
    to form a knitted helmet as disclosed in Schuessler I.
    2.
    The Board found that one of skill in the art would
    have reason to combine Nishida and the Schuessler
    References because these references are in similar fields
    and address the same problem. Nike asserts that the
    Board’s finding lacks substantial evidence because the
    16                                    NIKE, INC.   v. ADIDAS AG
    processes in these references are sufficiently different
    such that a person of skill in the art would not think to
    combine them. According to Nike, Nishida discloses a
    “subtractive” process, which requires the additional step
    of cutting the textile from a larger textile web. Nike
    contends that Nishida’s subtractive process bears no
    resemblance to the “additive” process in the Schuessler
    References, where the textile shape is created by flat
    knitting to shape in the first instance. Nike’s argument is
    not persuasive.
    In KSR, the Supreme Court instructed that “any need
    or problem known in the field of endeavor at the time of
    invention and addressed by the patent can provide a
    reason for combining the elements in the manner
    
    claimed.” 550 U.S. at 420
    . The three references all relate
    to the creation of three-dimensional, knitted articles
    created in an efficient and economical way by joining the
    edges of two-dimensional knit textiles. Nishida recogniz-
    es the desire to minimize the amount of wasted textile
    resulting from cutting the shoe upper pattern from a
    larger textile web. Schuessler I describes its preferred
    process, carried out by the flat-knitting machine in
    Schuessler II, for creating an article knitted to a specific
    shape “‘without requiring cutting.’” Adidas, 
    2014 WL 1713368
    , at *19 (emphasis in original) (quoting Schuess-
    ler I, 1:25–26). We thus agree with the Board that the
    prior art references “serve the same purpose” of efficiently
    creating knitted articles. See 
    id. And a
    skilled artisan
    interested in Nishida’s preference to minimize waste in
    the production process would have logically consulted the
    well-known practice of flat-knitting, which eliminates the
    cutting process altogether. In other words, a person of
    skill in the art would have been motivated to address the
    problem identified in Nishida by applying the teachings of
    the Schuessler References to arrive at the invention in
    Nike’s proposed substitute claims.
    NIKE, INC.   v. ADIDAS AG                                   17
    Nike next points to our decision in Leo Pharmaceuti-
    cals Products, Ltd. v. Rea, and argues that the age of
    these references and the passage of time between their
    public availability and the inventions recited in the pro-
    posed substitute claims should have precluded the Board
    from finding a reason to combine the references. 
    726 F.3d 1346
    , 1356–57 (Fed. Cir. 2013). Nike over reads our
    precedent. The relevant portion of Leo Pharmaceuticals
    stands for the proposition that the age of a reference can
    highlight the fact that no one in the art understood the
    problem to be solved.
    True enough, Leo Pharmaceuticals discusses the
    number of years that passed from the time the prior art
    was invented until the filing of the patent at issue. See
    
    id. at 1355,
    1356–57. But, our reversal of the Patent
    Board’s obviousness determination hinged on the fact that
    nothing in the cited prior art appreciated the problem the
    invention recognized and then solved. 
    Id. at 1353
    (“The
    ’013 patent, however, is not simply a combination of
    elements found in the prior art.                  The inven-
    tors . . . recognized and solved a problem . . . that the prior
    art did not recognize.”). Because there was no prior
    recognition of the problem solved by the subject invention,
    there was no reason in the record why one of skill in the
    art would attempt to combine the cited prior art to arrive
    at the claimed invention. 
    Id. at 1354
    (“Only after recog-
    nizing the existence of the problem would an artisan then
    turn to the prior art and attempt to develop [the claimed
    invention].”); see also 
    id. at 1356–57
    (rejecting an obvious-
    to-try argument because “[u]ntil the advancement made
    by the inventors . . . [t]he problem was not known, the
    possible approaches to solving the problem were not
    known or finite, and the solution was not predictable”).
    In this way, our decision in Leo Pharmaceuticals is
    entirely consistent with established precedent that “[t]he
    mere age of the references is not persuasive of the unobvi-
    ousness of the combination of their teachings, absent
    18                                    NIKE, INC.   v. ADIDAS AG
    evidence that, notwithstanding knowledge of the refer-
    ences, the art tried and failed to solve the problem.” In re
    Wright, 
    569 F.2d 1124
    , 1127 (CCPA 1977); see also Iron
    Grip Barbell Co. v. USA Sports, Inc., 
    392 F.3d 1317
    , 1325
    (Fed. Cir. 2004) (“Absent a showing of long-felt need or
    the failure of others, the mere passage of time without the
    claimed invention is not evidence of nonobviousness.”). 2
    Leo Pharmaceuticals recognizes the natural consequence
    of this idea: Persons of skill in the art cannot have tried
    and failed to solve the problem if they were never aware
    of that problem to begin with. Thus, the number of years
    that passed between the prior art and the claimed inven-
    tion may be a relevant factor to underscore that skilled
    artisans had long failed to appreciate the problem solved
    by that invention. Here, there is no question that skilled
    artisans knew of the desire to reduce waste when produc-
    ing wearable, knitted shoe uppers because that problem is
    expressly recognized in Nishida. Thus, Leo Pharmaceuti-
    cals does not control the present case.
    B. Secondary Considerations
    In Nike’s brief supporting the motion to amend filed
    at the Board, Nike argued that reducing waste was a
    long-felt need in the shoe manufacturing industry and
    that Nishida did not resolve this need because the process
    in Nishida still resulted in some waste. Nike specifically
    pointed to its expert’s declaration, which explained that
    Nishida shows that reducing material waste dur-
    ing manufacture of textile footwear uppers was a
    2  As discussed in the next section, we must remand
    for reconsideration of obviousness in light of Nike’s evi-
    dence of secondary considerations. As such, it may be
    appropriate for the Board to consider the passage of time
    in connection with Nike’s secondary considerations evi-
    dence on remand.
    NIKE, INC.   v. ADIDAS AG                                    19
    long-felt need. . . . Nishida’s response to this prob-
    lem was to make the “cutting waste” a simpler,
    lighter or cheaper material. . . . Unlike Nishida,
    which simply tried to make “cutting waste” less
    expensive, the upper of substitute claim 47 solves
    the long-felt need to reduce flat textile footwear
    upper manufacturing waste by eliminating the
    need to cut a textile element from a textile struc-
    ture, thereby eliminating “cutting waste” (and the
    associated cutting step) instead of simply making
    the cutting waste cheaper.
    J.A. 1647–48. Despite this argument and evidence, the
    Board’s final written decision lacks a discussion, or even
    an acknowledgement, of secondary considerations.
    1.
    Evidence of secondary considerations plays a critical
    role in the obviousness analysis because it serves as
    objective indicia of nonobviousness and “may often be the
    most probative and cogent evidence in the record. It may
    often establish that an invention appearing to have been
    obvious in light of the prior art was not.” Stratoflex, Inc.
    v. Aeroquip Corp., 
    713 F.2d 1530
    , 1538–39 (Fed. Cir.
    1983). It is well-established that “evidence rising out of
    the so-called ‘secondary considerations’ must always when
    present be considered en route to a determination of
    obviousness.” 
    Id. at 1538.
    In fact, we have expressly
    stated that “when secondary considerations are present
    . . . it is error not to consider them.” In re Kao, 
    639 F.3d 1057
    , 1067 (Fed. Cir. 2011) (emphasis added).
    Nike argues that the Board erred by failing to address
    secondary considerations. Neither Adidas nor the PTO
    disputes that the Board’s Final Written Decision lacks an
    acknowledgment of Nike’s secondary considerations
    evidence. Adidas instead argues that this omission is not
    an automatically reversible error. Similarly, the PTO
    argues that the Board did not err because it “implicitly
    20                                   NIKE, INC.   v. ADIDAS AG
    found that reducing waste was not a long-felt but unre-
    solved need.” Intervenor Br. 19 (emphasis added). Be-
    cause long-felt need is indisputably a secondary
    consideration, see 
    Graham, 383 U.S. at 17
    –18, our prece-
    dent dictates that the Board is bound to fully consider
    properly presented evidence on the long-felt need for a
    claimed invention. Recognizing that the Board operates
    under stringent time constraints, we do not hold that it is
    obliged to explicitly address conclusory and unsupported
    arguments raised by a litigant. Cf. Fresenius USA, Inc. v.
    Baxter Int’l, Inc., 
    582 F.3d 1288
    , 1296 (Fed. Cir. 2009)
    (holding that a party cannot preserve an argument if it
    presents “only a skeletal or undeveloped argument to the
    trial court”). Under the particular circumstances present-
    ed here, however, we conclude that the Board should have
    explicitly acknowledged and evaluated Nike’s secondary
    considerations evidence.
    2.
    Adidas attempts to minimize this gap in the Board’s
    decision by relying on our decisions stating that there is
    no requirement that a decision explicitly enumerate each
    Graham factor and include findings specifically in terms
    of the factors so long as “the required factual determina-
    tions were actually made and it is clear that they were
    considered while applying the proper legal standard of
    obviousness.” Specialty Composites v. Cabot Corp., 
    845 F.2d 981
    , 990 (Fed. Cir. 1988); see also MySpace, Inc. v.
    GraphOn Corp., 
    672 F.3d 1250
    , 1263–64 (Fed. Cir. 2012)
    (finding no error for failing to explicitly mention second-
    ary considerations because “the record establishe[d] that
    the evidence was properly before and considered by the
    [district] court”).
    Both Specialty Composites and MySpace are distin-
    guishable from the facts of this case. In these earlier
    cases, we were able to confirm that the respective district
    courts had weighed the evidence of secondary considera-
    NIKE, INC.   v. ADIDAS AG                                 21
    tions and reached a conclusion on that evidence because it
    was presented in written briefing and oral arguments
    and, critically, the courts made fact findings on that
    evidence. The absence of express recognition of secondary
    considerations was inconsequential. Specialty Compo-
    
    sites, 845 F.2d at 990
    (affirming the district court’s obvi-
    ousness determination because the record established
    that “the required factual determinations were actually
    made and it [was] clear that they were considered while
    applying the proper legal standard of obviousness”);
    
    MySpace, 672 F.3d at 1263
    –64 (finding no error for failing
    to explicitly mention secondary considerations because
    “the record establishe[d] that the evidence was properly
    before and considered by the [district] court”). Under
    these cases, we could perhaps be satisfied with the
    Board’s decision, even without it mentioning the second-
    ary considerations factor, if the decision had contained
    some findings indicating a basis for why the Board had
    rejected Nike’s evidence of long felt need. However, such
    findings are absent in this case. See Loctite Corp. v.
    Ultraseal Ltd., 
    781 F.2d 861
    , 873 (Fed. Cir. 1985) (“[W]e
    must be convinced from the opinion that the district court
    actually applied Graham and must be presented with
    enough express and necessarily implied findings to know
    the basis of the trial court’s opinion.”), overruled on other
    grounds by Nobelpharma AB v. Implant Innovations, Inc.,
    
    141 F.3d 1059
    (Fed. Cir. 1998).
    Contrary to the PTO’s arguments, the Board’s state-
    ments describing the teachings of the prior art do not
    amount to an “implicit” rejection of Nike’s long-felt-need
    evidence and argument. The Board made these state-
    ments in its motivation to combine analysis. See Adidas,
    
    2014 WL 1713368
    , at *19. Nothing in that discussion, or
    in any other part of the Board’s decision, suggests that
    the Board weighed and rejected Nike’s evidence of long-
    felt need to eliminate waste in the manufacture of knit
    textile uppers en route to concluding that the proposed
    22                                    NIKE, INC.   v. ADIDAS AG
    substitute claims were unpatentable as obvious. We must
    therefore remand for the Board to examine Nike’s evi-
    dence and its impact, if any, on the Board’s analysis
    under the first three Graham factors.
    3.
    Adidas finally argues that we can alternatively affirm
    the obviousness determination, despite the absence of
    findings on secondary considerations, because there is no
    nexus between Nike’s evidence and the merits of the
    invention in substitute claims 47–50. See In re GPAC
    Inc., 
    57 F.3d 1573
    , 1580 (Fed. Cir. 1995) (“For objective
    evidence [of secondary considerations] to be accorded
    substantial weight, its proponent must establish a nexus
    between the evidence and the merits of the claimed inven-
    tion.”). Whether the requisite nexus exists is a question of
    fact. Pro-Mold & Tool Co., Inc. v. Great Lakes Plastics,
    Inc., 
    75 F.3d 1568
    , 1573 (Fed. Cir. 1996). As such, we
    cannot resolve this factual dispute in the first instance.
    
    Comiskey, 554 F.3d at 974
    . We therefore express no
    opinion on this argument, except to recognize that the
    Board may certainly consider it on remand.
    C. Claim 49
    As mentioned above, Nike filed a motion to amend
    pursuant to 35 U.S.C. § 316(d) in which it sought to cancel
    the challenged patent claims and propose substitute
    claims. Section 316(d) provides that a patent owner’s
    ability to propose substitute claims is limited to proposing
    a “reasonable number of substitute claims.”               
    Id. § 316(d)(1)(B)
    (emphasis added). The PTO interpreted
    this limit in 37 C.F.R. § 42.121(a)(3) by explaining that
    “[t]he presumption is that only one substitute claim would
    be needed to replace each challenged claim.” The regula-
    tion also acknowledges that this presumption “may be
    rebutted by a demonstration of need.” 
    Id. In its
    Idle Free
    informative decision, the Board further explained that
    when a patent owner seeks to provide more than one
    NIKE, INC.   v. ADIDAS AG                                   23
    substitute claim for a challenged claim, “the patent owner
    needs to show patentable distinction of the additional
    substitute claim over all other substitute claims for the
    same challenged claim.” 
    2013 WL 5947697
    , at *5. If the
    patent owner fails to carry this burden, “then at the
    Board’s discretion, the proposed additional claim may be
    denied entry, or it may be grouped with, or deemed as
    standing and falling with, another substitute claim for the
    same challenged claim, e.g., the first substitute claim, for
    purposes of considering patentability over prior art.” 
    Id. Nike’s proposed
    substitute claims 48 and 49, both of
    which depend from substitute claim 47, recite:
    Claim 48. (Substitute for dependent claim 19)
    The article of footwear recited in claim [16] 47,
    wherein at least one of the first stitch configura-
    tion and the second stitch configuration forms an
    aperture in the [weft-knitted] flat knit textile el-
    ement and the joined edges shape the flat knit
    textile element to form a lateral region, a medial
    region, an instep region and a heel region of the
    upper.
    Claim 49. (Second substitute for dependent claim
    19) The article of footwear recited in claim [16] 47,
    wherein at least one of the first stitch configura-
    tion and the second stitch configuration forms [an
    aperture] a plurality of apertures in the [weft-
    knitted] flat knit textile element, the apertures
    formed by omitting stitches in the flat knit textile
    element and positioned in the upper for receiving
    laces.
    J.A. 1227. Claim 48 is directed to the general shape of the
    flat-knitted textile upper. Claim 49, on the other hand, is
    directed to a knit textile upper containing “apertures”
    that can be used to receive laces and that are formed by
    omitting stitches in the knit textile.
    24                                    NIKE, INC.   v. ADIDAS AG
    Thus, because Nike proposed substitute claims 48 and
    49 to replace challenged claim 19, under Idle Free, Nike
    was required to demonstrate that proposed claims 48 and
    49 were patentably distinct from one another. On appeal,
    Nike argues only that the Board erred in its treatment of
    claim 49 and asserts that the Board should have ultimate-
    ly found claim 49 patentable.
    1.
    The Board explained that, under Idle Free, whether
    both claim 48 and claim 49 could be substituted for origi-
    nal claim 19 depended on whether those claims were
    patentably distinct from each other. 3 Despite recognizing
    this standard, the Board proceeded to compare the limita-
    tions in each of these claims to the prior art. As to claim
    48, the Board observed that “Nishida describes joining the
    edges of the layout to form various portions of the upper.” 4
    Adidas, 
    2014 WL 1713368
    , at *12. With respect to claim
    49, the Board stated that “Nishida describes forming
    lacing areas by knitting.” 
    Id. The Board
    then concluded
    that Nike had not demonstrated “that claims 48 and 49
    are patentably distinct from each other.” 
    Id. Rather than
    deny entry of claims 48 and 49 on this basis, the Board
    decided to follow the alternate option provided in Idle Free
    and “group[ed] claim 49 with claim 48, for patentability
    purposes.” 
    Id. We agree
    with Nike that, despite correctly reciting
    the Idle Free standard that multiple substitute claims are
    permissible if they are patentably distinct from each
    other, the Board nevertheless did not engage in any such
    analysis comparing proposed substitute claims 48 and 49.
    3  Neither party objects to Idle Free’s interpretation
    of 37 C.F.R. § 42.121(a)(3) or to the PTO’s interpretation
    of § 316(d)(1)(B) in section 42.121(a)(3).
    4  Nike does not dispute this conclusion.
    NIKE, INC.   v. ADIDAS AG                                    25
    Thus, the Board’s decision to group substitute claims 48
    and 49 together, meaning that claim 49 would stand and
    fall with claim 48, is not consistent with the rule set out
    by the Board in Idle Free. The Board has not provided a
    supported basis for grouping the two claims together in
    this manner. We must therefore remand for a proper
    determination of how these claims should be treated per
    the standard set forth in Idle Free, and, if necessary, a full
    consideration of the patentability of each.
    2.
    Even though the Board did not engage in the proper
    analysis to group claims 48 and 49 together, Adidas
    argues that Nike never separately argued the patentabil-
    ity of claim 49, and for that reason it was appropriate to
    nevertheless find claim 49 unpatentable. Contrary to
    Adidas’s assertion, Nike did argue to the Board that claim
    49 was separately patentable. In its motion to amend,
    Nike explained that “Nishida also does not disclose the
    limitation of claim 49 regarding apertures.” J.A. 1233.
    Nike supported this argument with its expert declaration:
    Nishida also does not teach the limitation requir-
    ing “a plurality of apertures in the flat knit textile
    element, the apertures formed by omitting stitch-
    es in the flat knit textile element and positioned
    in the upper for receiving laces.” While figure 3 of
    Nishida indicates the upper includes openings for
    laces, Nishida contains no description or sugges-
    tion of forming such openings by omitting stitches
    in the layout. Thus, it appears such openings
    were created by an additional manufacturing step,
    e.g., punching out the openings.
    J.A. 1610.
    Adidas seems to imply that Nike insufficiently pre-
    served the argument by raising it only in its motion to
    amend and not in its reply brief. An issue is preserved for
    26                                    NIKE, INC.   v. ADIDAS AG
    appeal, however, so long as it can be said that the tribu-
    nal was “‘fairly put on notice as to the substance of the
    issue.’” Consolidation Coal Co. v. United States, 
    351 F.3d 1374
    , 1378 (Fed. Cir. 2003) (quoting Nelson v. Adams
    USA, Inc., 
    529 U.S. 460
    , 469 (2000)). Nike raised this
    argument in its motion to amend and supported the
    argument with its expert declaration. This was sufficient
    to put the Board on notice that Nike was asserting the
    “apertures formed by omitting stitches . . . and . . . for
    receiving laces” limitation as a patentable distinction. We
    therefore cannot agree with Adidas that Nike has waived
    its arguments relating to the patentability of claim 49.
    3.
    Adidas also argues that we can nevertheless affirm
    the Board’s conclusion that claim 49 is unpatentable in
    light of Nishida and the Schuessler References. Adidas
    even asserts that the Board itself engaged in this analysis
    and found that the additional limitations in claim 49 were
    disclosed in Nishida. To support this argument, Adidas
    points to the Board’s above-mentioned, less-than-clear
    analysis purporting to analyze whether claims 48 and 49
    were “obvious over each other.”        Adidas, 
    2014 WL 1713368
    , at *12.
    Claim 49 adds the limitation: “a plurality of aper-
    tures . . . formed by omitting stitches in the flat knit
    textile element and positioned in the upper for receiving
    laces.” J.A. 1227. The Board merely explained that
    “[w]ith respect to the additional limitations of claim 49,
    Nishida describes forming lacing areas by knitting.
    Further, the Specification of the ’011 Patent describes the
    omission of stitches, as recited in claim 49, to provide air
    permeability to the upper.” Adidas, 
    2014 WL 1713368
    , at
    *12 (citations omitted). The Board supported its conclu-
    sion that “Nishida describes forming lacing areas by
    knitting,” by first citing to (but not discussing) Nishida’s
    NIKE, INC.   v. ADIDAS AG                                 27
    specification, which describes the concept of shoe laces
    and lacing areas, as seen in Figures 2 and 3 of Nishida:
    [T]he material can be woven or knitted in two or
    more layers or can be especially thick or addition-
    ally embroidered. Similarly, the lacing areas 23
    and 24 can be made dimensionally stable in corre-
    sponding manners, especially if, for example, no
    additional trimmings, such as the lacing strips 25,
    shown in FIG. 3, are to be applied.
    ’638 patent, 3:67–4:5.
    ’638 patent, Figure 2 (illustrating lacing areas 23 and 24
    in Nishida’s knit textile upper pattern).
    28                                    NIKE, INC.   v. ADIDAS AG
    ’638 patent, Figure 3 (depicting a completed shoe with the
    optional lacing strips 25 attached to lacing area 23 or 24).
    In this same discussion, the Board also pointed to Nike’s
    own patent, the ’011 patent, because it “describes the
    omission of stitches . . . to provide air permeability to the
    upper.” 5 
    Id. (citing ’011
    patent, 9:57–62). Finally, the
    Board cited, in a parenthetical, to Nishida’s disclosure
    that the toe area of the upper can have “good air exchange
    capability . . . by [using] a net-like woven or knitted
    structure.” ’638 patent, 3:49–52. The Board did not
    provide any explanation of the relevance of this passage
    nor the conclusions that it drew therefrom. Nevertheless,
    from these passages, the Board concluded that Nike had
    5  We are troubled by the Board’s citation to the ’011
    patent’s written description and the corresponding ap-
    pearance of using the ’011 patent to find claim 49 un-
    patentable. Given the confusing analysis of comparing
    the substitute claims to the prior art to conclude that the
    substitute claims are not patentably distinct from one
    another, we are unsure for what purpose the Board was
    referring to the ’011 patent’s written description. This
    confusion can also be resolved on remand.
    NIKE, INC.   v. ADIDAS AG                                 29
    not demonstrated that claims 48 and 49 were patentably
    distinct from one another and then decided to group the
    two proposed substitute claims together for patentability
    purposes. At no point did the Board refer to the Graham
    factors and conclude that Nishida renders proposed
    substitute claim 49 obvious.
    The Board’s statements are insufficient to support a
    conclusion that proposed substitute claim 49 is unpatent-
    able as obvious. As discussed above, obviousness deter-
    minations require underlying fact-findings, many of
    which are missing from the Board’s decision as it relates
    to the specific limitations in claim 49. Adidas contends
    that no additional fact-finding is needed by pointing to the
    holes in the lacing area depicted in Nishida’s Figure 3.
    But, the Board did not point to any disclosure in Nishida
    that explains the manner in which these holes were
    created, whether through knitting or some other way. In
    fact, the Board’s short discussion did not even address the
    presence of the holes in either claim 49 or Nishida. Fur-
    ther, Nishida’s specification never specifically discusses
    the lacing holes of its upper; they are only shown in
    Figure 3. It may well be that the Board intended to
    convey that claim 49 was obvious in light of Nishida
    because skipping stitches to form apertures, even though
    not expressly disclosed in Nishida, was a well-known
    technique in the art and that understanding perhaps
    would be a basis to conclude that one of skill in the art
    would utilize this technique to create holes for accepting
    shoe laces. 6 But, the Board did not articulate these
    6   Adidas also asserts that the manner in which the
    lacing holes are created is irrelevant because the “formed
    by omitting stitches” portion of the limitation is nothing
    more than a product-by-process limitation. Because this
    was not raised to the Board during the IPR proceedings,
    we decline to opine on the issue except to say that, if given
    30                                   NIKE, INC.   v. ADIDAS AG
    findings. This portion of the Board’s analysis on whether
    Nike’s proposal of claim 48 and 49 constituted a reasona-
    ble number of substitute claims for originally issued claim
    19 lacks critical fact-findings needed for any obviousness
    determination. We are unable to engage in such fact-
    finding in the first instance and must therefore remand
    for further proceedings. See 
    Ariosa, 805 F.3d at 1365
    (“But we must not ourselves make factual and discretion-
    ary determinations that are for the agency to make.”).
    4.
    Nike, on the other hand, requests that we reverse and
    find claim 49 patentable because Nishida does not dis-
    close the formation of apertures by omitting stitches.
    Nike specifically argues that the Board misunderstood the
    scope of claim 49 and the disclosure of Nishida. According
    to Nike, the Board failed to realize that claim 49 requires
    more than just knit “lacing areas,” but requires apertures
    formed from skipping stitches in the knit pattern in an
    orientation such that the resulting apertures are capable
    of accepting shoe laces. See Adidas, 
    2014 WL 1713368
    , at
    *12 (“With respect to the additional limitations of claim
    49, Nishida describes forming lacing areas by knitting.”).
    To support this argument, Nike points to its expert,
    who opined that, “[w]hile figure 3 of Nishida indicates the
    upper includes openings for laces, Nishida contains no
    description or suggestion of forming such openings by
    omitting stitches in the layout. Thus, it appears such
    the opportunity, Adidas may raise this argument to the
    Board on remand. See Ariosa Diagnostics v. Verinata
    Health, Inc., 
    805 F.3d 1359
    , 1367 (Fed. Cir. 2015) (“We do
    not direct the Board to take new evidence or, even, to
    accept new briefing. The Board may control its own
    proceedings, consistent with its governing statutes, regu-
    lations, and practice.”).
    NIKE, INC.   v. ADIDAS AG                                  31
    openings were created by an additional manufacturing
    step, e.g., punching out the openings.” J.A. 1610. Nike
    asserts that this interpretation of the lacing holes in
    Nishida is correct based on Nishida’s explanation that the
    knit upper “can be provided with an embroidery, especial-
    ly with an English embroidery (i.e., the type of embroi-
    dery by which a hole pattern is welded and which is
    commonly used for the sewing of button holes), of a
    trademark or another mark or identification on suitable
    or preferred places.” ’638 patent, 4:33–38. Nike’s expert
    further opined that there would have been “no motivation
    or other reason that would have prompted one of ordinary
    skill in the art at the time of the invention to modify
    Nishida to include this additional feature.” J.A. 1613.
    Based on this evidence, Nike urges us to find claim 49
    patentable. We are unable to do so on this record be-
    cause, as already explained, the Board has not made the
    requisite factual findings. Importantly, there are no
    findings from the Board about the scope and content of
    the passages from Nishida’s written description on which
    Nike now relies. Further, there is no discussion about
    whether Nike’s expert’s statement was sufficient to
    demonstrate that there was no motivation to modify
    Nishida to arrive at lace holes formed by omitting stitch-
    es. Thus, we cannot, as Nike requests, reverse and find
    claim 49 patentable. Any resolution of this issue requires
    a factual analysis that must be done by the Board in the
    first instance.
    III.      Adidas’s Alternative Grounds for Affirmance
    Adidas also argues that, even if we cannot affirm the
    Board’s obviousness conclusion, there are numerous
    alternative grounds on which we could affirm claim 49’s
    unpatentability. First, Adidas argues that the Board’s
    construction of “flat knit edges” is overly narrow and that,
    under the correct construction, Nishida anticipates all of
    the proposed substitute claims. Second, Adidas asserts
    32                                      NIKE, INC.   v. ADIDAS AG
    that, even under the Board’s construction, Nishida alone
    renders the proposed substitute claims obvious. Finally,
    Adidas contends that we should affirm the outcome
    reached by the Board because, contrary to the Board’s
    decision, Nike’s proposed substitute claims are inade-
    quately supported by the ’011 patent’s written descrip-
    tion.
    1.
    We review the Board’s ultimate claim construction de
    novo and any underlying factual determinations involving
    extrinsic evidence for substantial evidence. Teva Pharm.
    U.S.A., Inc. v. Sandoz, Inc., 
    135 S. Ct. 831
    , 841–42 (2015).
    When, as here, the intrinsic record fully determines the
    proper construction, we review the Board’s claim con-
    struction de novo. 
    Id. at 840–42;
    see also 
    Proxyconn, 789 F.3d at 1297
    .
    Each of Nike’s proposed substitute claims is directed
    to a “flat knit textile element . . . having flat knit edges
    free of surrounding textile structure.” Before the Board,
    Adidas argued that the broadest reasonable interpreta-
    tion of “flat knit edges” should encompass not only flat-
    knit edges that are created when a flat knit textile ele-
    ment is knit to shape, but also edges created from cutting
    a textile element from a larger textile. The Board disa-
    greed and determined that the broadest reasonable con-
    struction of the term “flat knit edges” is “an edge of a flat
    knit textile element, which is itself flat knit, e.g., which is
    not formed by cutting from a flat knit textile element.”
    Adidas, 
    2014 WL 1713368
    , at *9. The Board arrived at
    this interpretation because any broader interpretation
    would be inconsistent with “the context of this claim
    (including surrounding claim language) and in the context
    of the Specification of this patent.” 
    Id. (emphasis in
    original).
    On appeal, Adidas again argues that the Board erred
    because “flat knit edge” does not preclude edges formed by
    NIKE, INC.   v. ADIDAS AG                                 33
    cutting. We agree with the Board’s construction. The
    language of proposed substitute claim 47 expressly recites
    that a “flat knit textile element, the flat knit textile
    element having flat knit edges free of surrounding textile
    structure from which the textile element must be removed .
    . . .” J.A. 1226 (emphasis added). This claim language
    demonstrates that the scope of this claim is limited to a
    flat-knit textile element where the flat knit edges have
    not been removed, or cut, from a surrounding textile
    structure. An interpretation that included a flat-knit
    textile element that has been cut from a larger textile web
    would contradict the express claim language. 7
    We therefore affirm the Board’s conclusion that the
    broadest reasonable interpretation of “flat knit edge” is
    “an edge of a flat knit textile element, which is itself flat
    knit, e.g., which is not formed by cutting from a flat knit
    textile element.” Because we affirm the Board’s construc-
    tion of the term “flat knit edges,” we need not consider
    Adidas’s argument that Nishida would anticipate under
    Adidas’s proposed construction.
    2.
    Adidas next argues that, even if we affirm the Board’s
    construction of “flat knit edges,” we should nevertheless
    affirm the Board’s conclusion that the proposed substitute
    claims are unpatentable because Nishida alone, without
    the Schuessler References, renders the claims obvious.
    This argument also fails.
    A single-reference obviousness conclusion would avoid
    only the question of whether there existed a motivation to
    7   Because Adidas is requesting an even broader
    construction than the broadest reasonable instruction, our
    conclusion that Adidas’s construction is incorrect would
    not change under the standard used in district court
    proceedings.
    34                                    NIKE, INC.   v. ADIDAS AG
    combine the teachings of Nishida and the Schuessler
    References. We have already found the Board’s finding on
    this question supported by substantial evidence. Adidas’s
    single-reference obviousness argument does not, however,
    resolve the Board’s failure to address Nike’s evidence of
    secondary considerations. We therefore reject this argu-
    ment as an alternative ground to affirm on the record
    before us.
    3.
    Adidas finally asserts that we should affirm the
    Board’s conclusion that the proposed substitute claims are
    unpatentable because they lack adequate written descrip-
    tion support. Whether a claim is supported by the pa-
    tent’s written description is a question of fact that we
    review for substantial evidence. See Ariad Pharm., Inc. v.
    Eli Lilly & Co., 
    598 F.3d 1336
    , 1355 (Fed. Cir. 2010) (en
    banc); In re Morsa, 
    713 F.3d 104
    , 109 (Fed. Cir. 2013)
    (factual determinations by the Board are reviewed for
    substantial evidence).
    To adequately support the claims, the written de-
    scription “must clearly allow persons of ordinary skill in
    the art to recognize that the inventor invented what is
    claimed.” 
    Ariad, 598 F.3d at 1351
    (internal quotation
    marks omitted). “Substantial evidence supports a finding
    that the specification satisfies the written description
    requirement when the essence of the original disclosure
    conveys the necessary information—regardless of how it
    conveys such information, and regardless of whether the
    disclosure’s words are open to different interpretations.”
    Inphi Corp. v. Netlist, Inc., 
    805 F.3d 1350
    , 1354 (Fed. Cir.
    2015) (internal quotation marks omitted); see also In re
    Ruschig, 
    379 F.2d 990
    , 995 (CCPA 1967) (the written
    description requirement serves the same function as
    “blaze marks on the trees” to help “find[] one’s way
    through the woods”).
    NIKE, INC.   v. ADIDAS AG                                 35
    Adidas argued that the “flat knit edge” limitation was
    a negative limitation. Adidas further argued that nega-
    tive limitations must satisfy a heightened written descrip-
    tion requirement under our decision in Santarus, Inc. v.
    Par Pharmaceutical, Inc., 
    694 F.3d 1344
    (Fed. Cir. 2012).
    The Board disagreed and concluded that, even if the
    limitation was a negative limitation, it was “supported by
    the positive disclosure of the various forms of the textile
    element” shown in the ’011 patent’s written description.
    Adidas, 
    2014 WL 1713368
    , at *9.
    On appeal, Adidas again argues that the term “flat
    knit edge” is a negative limitation and as such it must
    satisfy a “heightened requirement” of written description
    support. Appellant’s Br. 51 (citing 
    Santarus, 694 F.3d at 1351
    ). It is worth noting that we doubt that the present
    limitation is properly characterized as a negative limita-
    tion. Negative limitations generally recite an express
    exclusion of material. For example, in Inphi, we ad-
    dressed claim language that expressly excluded the use of
    certain signal types in a claim relating to computer sys-
    tem memory modules. 
    Inphi, 805 F.3d at 1352
    –53 (“the
    chip selects of the first and second number of chip selects
    are DDR chip selects that are not CAS, RAS, or bank
    address signals” (emphasis added)). Similarly, in Santa-
    rus, we examined claim language that expressly excluded
    the use of sucralfate in a claim directed to the treatment
    of an acid-caused gastrointestinal disorder. 
    Santarus, 694 F.3d at 1350
    (“wherein the composition contains no su-
    cralfate”).
    Even if we assume, as the Board did, that this claim
    limitation is a negative limitation, Adidas is incorrect that
    any sort of heightened standard applies. “Negative limi-
    tations are adequately supported when the specification
    describes a reason to exclude the relevant limitation.” 
    Id. at 1351.
    We recently explained in Inphi that, contrary to
    Adidas’s argument, Santarus did not create a heightened
    36                                    NIKE, INC.   v. ADIDAS AG
    standard for written description support of negative
    limitations. 
    Inphi, 805 F.3d at 1356
    . We further ex-
    plained that “[w]hen viewed in its proper context, Santa-
    rus simply reflects the fact that the specification need
    only satisfy the requirements of § 112, paragraph 1 as
    described in this court’s existing jurisprudence.” 
    Id. (citing MPEP
    § 2173.05(i) (“If alternative elements are
    positively recited in the specification, they may be explic-
    itly excluded in the claims.”)). Thus, we need only consid-
    er whether the disclosures of the ’011 patent, using the
    customary standard for the written description require-
    ment, allow persons of ordinary skill in the art to recog-
    nize that the inventor invented a flat-knit textile with
    flat-knit edges that are knit to shape rather than being
    cut from a larger textile web.
    In reaching its conclusion that the proposed substi-
    tute claims were supported by the ’011 patent’s written
    description, the Board emphasized Figures 8, 10, and 11.
    ’011 patent, Figures 8, 10, 11. These figures illustrate the
    shape of textile element 40 before the formation of seams
    to create the general shape for receiving a foot. Even
    Adidas’s expert agreed that the upper illustrated in
    Figure 8 “could be made on a flat knitting machine” and
    “then the edges that are shown in Figure 8 would be flat
    knitted.” J.A. 1483; see also J.A. 1574 (Nike’s expert
    NIKE, INC.   v. ADIDAS AG                                37
    opining that “[t]he disclosure in the ’011 patent that the
    textile elements in Figures 8, 10, and 11 can be made
    using flat knitting makes it clear that these textile ele-
    ments can be knit to the shapes shown in these figures
    (i.e., without surrounding textile structure) using flat
    knitting.”).
    These figures are in sharp contrast to Figure 9, which
    is formed using a “wide-tube circular knitting machine,”
    as opposed to a flat-knitting machine. ’011 patent, 6:66–
    7:8, 7:41–43; see also 
    id. at 7:29–32
    (explaining that a
    circular knitting machine “forms a generally cylindrical
    textile structure”).
    ’011 patent, Figure 9. As shown in Figure 9, a circular
    knit upper, as distinguished from flat knit, must be
    removed from surrounding textile material by, for exam-
    ple, cutting. In addition, Nike’s expert explained that the
    embodiment illustrated in Figure 9 is made “using a
    circular knitting process and requires that the textile
    element [40] be formed as part of a larger textile structure
    38                                    NIKE, INC.   v. ADIDAS AG
    [60]” and “requires additional processing to remove the
    textile element [40] from the textile structure [60].” J.A.
    1571. The Board agreed with Nike that the language
    describing Figure 9 “does not limit the textile elements
    depicted in Figures 8, 10, and 11 to those manufactured
    according to the process of Figure 9.” Adidas, 
    2014 WL 1713368
    , at *15.
    In addition, the Board cited Nike’s expert’s declara-
    tion explaining that the textile upper shown in Figures 8,
    10, and 11 “‘illustrates multiple examples in which the
    textile element is shown in its final shape and is not
    described as being formed as part of a larger textile
    structure from which it must be removed.’” 
    Id. (quoting J.A.
    1587). The written description and the originally
    issued claims make a distinction between textile elements
    that are removed from a larger textile web and those that
    are not. For example, the patent discusses the textile
    element 40 as “a single material element that is formed to
    exhibit a unitary (i.e., one-piece) construction.” ’011
    patent, 5:38–39. The patent then explains that “[t]extile
    element 40 may be formed as a part of a larger textile
    element,” which would then require that “textile element
    40 is . . . removed from the larger textile element.” 
    Id. at 5:43–45.
    In fact, only one of the originally issued, now
    cancelled, independent claims is expressly directed to an
    upper where “the textile element [is] removed from a
    textile structure.” 
    Id. at 13:47–14:6
    (claim 36). Accord-
    ingly, based on the Figures in the ’011 patent, the disclo-
    sures in the written description, and the expert
    testimony, we conclude that substantial evidence supports
    the Board’s decision that the proposed substitute claims
    are adequately supported by the written description of the
    ’011 patent.
    NIKE, INC.   v. ADIDAS AG                                 39
    IV. Establishing Patentability Over Prior Art Not of
    Record But Known to the Patent Owner
    The Board’s Idle Free decision explained that, under
    37 C.F.R. § 42.20(c), a motion to amend will be successful
    only if the patent owner “persuade[s] the Board that the
    proposed substitute claim is patentable over the prior art
    of record, and over prior art not of record but known to the
    patent owner.” 
    2013 WL 5947697
    , at *4 (emphasis added).
    Nike attempted to carry this burden in its motion to
    amend by simply stating that its proposed claims were
    patentable over prior art known to Nike, but not part of
    the record of the proceedings. See J.A. 1228. The Board
    denied Nike’s request to enter proposed substitute claims
    47–50 in part because Nike’s motion failed to address any
    prior art reference that was not discussed in Adidas’s
    petition for review or Adidas’s opposition to Nike’s motion
    to amend, i.e., any prior art not of record. Adidas, 
    2014 WL 1913368
    , at *17 (finding Nike’s “conclusory state-
    ment” to be “facially inadequate” under the Board’s un-
    derstanding of Idle Free). As discussed above, as an
    alternative ground to deny Nike’s motion, the Board went
    on to consider the patentability of Nike’s proposed substi-
    tute claims on the merits. Because we must vacate and
    remand the Board’s obviousness conclusion, we must now
    consider whether the Board’s denial of Nike’s motion to
    amend for failure to show patentable distinction over
    “prior art not of record but known to the patent owner”
    provides an adequate basis for affirmance. For the rea-
    sons explained below, we conclude that it is not.
    After the Board’s decision in this case, the Board is-
    sued MasterImage 3D, Inc. v. RealD Inc., IPR2015-00040,
    
    2015 WL 4383224
    (PTAB July 15, 2015), which has been
    designated by the PTO as a Representative Decision on
    Motions to Amend. See Standard Operating Procedure 2,
    at 3 (¶ IV.A–B) (explaining that Board decisions labeled
    “representative” are “not binding authority,” but provide
    “a representative sample of outcomes on a matter”). In
    40                                    NIKE, INC.   v. ADIDAS AG
    MasterImage 3D, the Board “ma[d]e three points of clari-
    fication regarding” Idle Free’s requirement that the patent
    owner show that its proposed substitute claims are pa-
    tentable over the prior art of record and also other prior
    art known to the patent owner. Importantly, the Board
    explained that “[t]he reference to ‘prior art known to the
    patent owner’ . . . in Idle Free, should be understood as no
    more than the material prior art that Patent Owner
    makes of record in the current proceeding pursuant to its
    duty of candor and good faith to the Office under 37
    C.F.R. § 42.11, in light of the Motion to Amend.” Master-
    Image 3D, Slip. Op. at 3. At oral argument in the present
    case, the PTO confirmed this characterization of Master-
    Image 3D. See Oral Argument at 29:13–29:22 available at
    http://cafc.uscourts.gov/oral-argument-recordings/2014-
    1719/all (“[MasterImage] is not a change of Idle Free, it’s
    more of a clarification of Idle Free.”). The PTO further
    explained that, although the Board’s denial of Nike’s
    motion to amend was based on a reasonable reading of
    Idle Free, given the clarification in MasterImage 3D, the
    PTO acknowledged that the Board “read Idle Free too
    aggressively in this decision.” 
    Id. at 29:23–30:01.
        We agree with the PTO. At the heart of Idle Free, as
    interpreted by MasterImage 3D, is the question of wheth-
    er the patent owner has submitted the necessary infor-
    mation to comply with its duty of candor to the office. In
    this case, there is not, and there has never been, an
    allegation that Nike violated its duty of candor. Moreo-
    ver, the PTO acknowledged that Nike’s statement about
    the substitute claims’ patentability over prior art not of
    record but known to Nike would satisfy the obligation as
    explained in MasterImage 3D. 
    Id. at 35:50–36:06.
    After
    MasterImage’s explanation of Idle Free, we cannot see
    how the statement used by Nike would be inadequate,
    absent an allegation of conduct violating the duty of
    candor. We therefore conclude that this was an improper
    ground on which to deny Nike’s motion to amend.
    NIKE, INC.   v. ADIDAS AG                              41
    CONCLUSION
    For the foregoing reasons, we vacate the Board’s obvi-
    ousness determination and remand for further proceed-
    ings consistent with this opinion.
    AFFIRMED-IN-PART, VACATED-IN-PART, AND
    REMANDED
    COSTS
    No costs.