What are the acceptable formats for patent drawings?

According to 37 CFR 1.84(a), there are two acceptable categories for presenting drawings in utility and design patent applications:

1. Black ink drawings: Black and white drawings are normally required. India ink or its equivalent must be used to secure solid black lines.
2. Color drawings/photographs: Color drawings are permitted in design applications without a petition. For utility applications, color drawings or photographs require a granted petition explaining why color is necessary.

Additionally, grayscale drawings and black and white photographs may be acceptable in certain circumstances, such as when they are the only practicable medium for illustrating the claimed invention.

To learn more:

• patent drawings
• drawing formats
• color drawings