Design Patent Application Drawings & Prosecution History Must Be Clear (Merely Translucent Won’t Suffice!)

Design patents offer protection for the ornamental appearance of a product, focusing on aspects like its shape and surface decoration, as opposed to the functional aspects protected by utility patents. The scope of a design patent is defined by the drawings and any descriptive language within the patent itself. Recent decisions by the Federal Circuit emphasize the need for clarity in the prosecution history of a design patent in order to preserve desired scope to preserve intentional narrowing (and to avoid unintentional sacrifice of desired claim scope).

The Federal Circuit’s recent precedential decision in Smartrend Manufacturing Group, Inc. v. Opti-Luxx Inc.  illustrates the importance of an accurate description in a design patent. At the district court, Smartrend prevailed against Opti-Luxx in alleging infringement of a design patent (U.S. D932,930) for an illuminated light panel. The key issue on appeal was the district court’s construction of “transparency.” The district court had instructed the jury that “transparency” meant both “transparent and translucent.” The Federal Circuit strongly disagreed.

A patented design may be claimed simply with a drawing, but the Manual of Patent Examining Procedure (“MPEP”) permits applicants to use a description to detail the appearance of portions of the claimed design not illustrated in the drawing. MPEP 1503.01 (II)(A)(1). Smartrend set forth such a description in their design patent. The drawings in the patent used oblique line shading, which the MPEP states is used to show “transparent, translucent and highly polished or reflective surfaces, such as a mirror.” MPEP 1503.02 (II).  The Court noted that the oblique shading lines on their own would thus encompass “translucent.” However, Smartrend’s accompanying description specifically stated that the patent’s oblique shading lines “denote transparency.” The Court held that this description expressly narrowed the scope and limited the claims to surfaces that possess transparency only. The Court thus vacated the judgement of infringement and remanded for a new trial due to the lower court’s misconstrual of “transparency.”

In a decision earlier this year, the Federal Circuit held that the doctrine of prosecution history disclaimers applies to design patents, just as it does to utility patents. Top Brand LLC v. Cozy Comfort Co., 143 F.4th 1349, 1358 (Fed Cir. 2025). Under this doctrine, a practitioner may surrender claim scope during prosecution of a patent through both amendment and argument. In Top Brand, the patent holder had overcome the prior art rejection by arguing that the pocket shape and sleeve positioning of their sweatshirt design was different, surrendering claim scope with regard to these features. Because the patent holder relied only on the disclaimed features to show design similarity in their subsequent infringement claim, the Court found there was no infringement.

Ultimately, these decisions serve as a clear reminder of the critical importance of precision and consistency throughout all phases of the design patent process. For patent owners and applicants, every word in a patent’s written description—including technical terms and explanations that accompany the drawings—can decisively narrow the scope of protection. Seemingly small choices in language during prosecution, or in distinguishing prior art, can amount to binding disclaimers, limiting what features can later be asserted in court. Likewise, in litigation, claim construction will hinge on both intrinsic evidence and how terms are used with deliberate specificity; parties should not expect courts to broaden claim terms beyond their plain and ordinary meaning, especially when the patent’s own specification defines the term more narrowly. On the other hand, intentional choices of disclaimer in text and drawings can be used strategically to avoid prior art and to avoid indefiniteness. 

The takeaway for both patent owners and potential challengers is that design patent strategy demands careful drafting and proactive prosecution decisions. Attention to detail in claim language, well-considered use of descriptions, and mindful prosecution arguments are crucial to securing and defending meaningful patent rights.

Crowell would like to thank Savannah Gabriel for her contribution to this alert.