Given that design patents cover the appearance of an invention, it’s especially important for inventors to include appropriate drawings of the design in question. A good way to start is by imagining that you are holding the article that the design is a part of within a cube. Looking at this cube, draw the article within from the top, bottom, left, right, front, and back. Any other perspectives that help to capture important elements of the design should also be included.
While surface shading is not required, it may be necessary or helpful in certain cases to use shading in order to clearly show the character and contour of three-dimensional aspects of the design, or to distinguish between open and solid areas. However, surface shading should not be used on any unclaimed subject matter—shown in broken lines—in order to avoid confusion with regard to the scope of the claimed design.
Broken lines are most commonly used to illustrate the environment related to the claimed design, and to define the boundaries of the claimed design. Any structures that are not part of the claimed design, but are considered necessary to depict in order to show the design’s environment may be represented in the drawing(s) with broken lines. Stitching on fabric is commonly shown in broken lines. That stitching can either be part of the claimed design or not depending on what is in the specification.
While there is a downside to using broken lines, as it limits any damages to the design aspects illustrated with solid lines, the use of broken lines typically allows design protections to be enforceable in a larger context.
Once upon a time, it was common to use photographs instead of drawings in design patents. That doesn’t work anymore. If the only way to show a design is with photographs, you have to make that really clear to the patent office or it will ask you to replace the photos with drawings.