What type of ink is required for patent application documents?

According to MPEP 714.07, patent application documents must be submitted using permanent dark ink or its equivalent. This requirement is specified in 37 CFR 1.52(a). The MPEP states:

37 CFR 1.52(a) requires ‘permanent dark ink or its equivalent’ to be used on papers which will become part of the record.

This ensures that the documents will be legible and durable for long-term record-keeping purposes.

To learn more:

• patent application
• ink requirements
• document submission
• patent office rules