Inventors often include drawings when they submit a patent application. These drawings help the patent examiner understand the invention and determine if it can be patented.You can find the rules that govern these drawings in the Manual of Patent Examining Procedures, or MPEP. These rules are rather complex, so many patent attorneys hire special draftsmen who are familiar with the legal requirements. Some online document providers also include preparation of drawings among their patent filing services.
Necessity of Drawings
The United States Patent and Trademark Office requires one or more drawings of an invention "where necessary for the understanding of the subject matter to be patented." These drawings can include flow charts for computer programs, cross sections showing the interior of the invention, exploded drawings showing how the invention is assembled and flow charts of procedures. In practice, most utility patents and all design patents include drawings.
If a drawing is not included and the patent examiner determines that a drawing is necessary, the patent drawing rules state that the United States Patent and Trademark Office will treat the patent application as if it were incomplete. This means that the filing date of the application will be delayed until the inventor provides a drawing. In highly competitive fields, this postponement might render an invention unpatentable.
Drawings should be in black and white. The drafter should make them using India ink or a comparable equivalent that makes solid black lines. These drawings should be on the same size white paper -- 8 1/12 by 11 inches -- or on A4 paper. The top and left margins should be at least 1 inch; the bottom margin should be at least 3/8 of an inch and the right should be at least 5/8 of an inch.
The United States Patent and Trademark Office allows color drawings when color is an integral part of the invention or when it is necessary to understand an element of the invention, such as a electrophoresis gel or other experimental finding. CFR 184 (a)(2) states that inventors must submit an additional petition to the United States Patent and Trademark Office and pay an additional fee if they submit colored drawings.