Broken Lines in Design Patent Drawings

Dipika Shaw
Jun 18
2 min read

A broken-line disclosure is understood to be for illustrative purposes only and forms no part of the claimed design. Elements that are not part of the claimed design, but are necessary to show the environment in which the design is used, may be illustrated using broken lines. This may include portions of the article to which the design is applied or embodied that are not being claimed. When the claim is directed solely to surface ornamentation, the article bearing the ornamentation must be shown in broken lines.

The example below illustrates a Box Lid with a Handle design. Without the broken or stippled lines representing the box lid, it would be unclear where the handle design is applied, resulting in a disembodied design. Therefore, it is necessary to show the article or environment in which the design is used. Since the box lid itself is not part of the claimed design, it is depicted in broken lines.

In industrial design drawings, stippled lines are used for two primary purposes: to indicate unclaimed portions of a design and to represent stitching on fabric or textile products. When both stitching and unclaimed portions appear in the same drawing, the unclaimed portions should be illustrated using dotted lines to clearly distinguish them from the stitching details.

Below showing an example of fabric with stiches in dash line and manequin is shown using dotted lines.

Broken lines and dotted lines to distinguish between stiches and unclamied design.

It is important to note that industrial design patent drawings differ from conventional mechanical engineering drawings. In engineering drafting, hidden features are typically represented using dashed lines. However, in industrial design illustrations, dashed lines are not used to show hidden features of opaque objects. Instead, only the visible portions of the design are illustrated. If an object is transparent or translucent, the features visible through the surface may be shown using lighter lines to indicate transparency.

Below showing an example of transparent object showing in lighter layer and unclaimed parts in dash lines.