If I'm patenting a design, do I need to keep documentation?

Filing a patent application provides the U.S. Patent and Trademark Office with relatively strong proof of your design's conception and practice date. However, it's always a good idea to maintain records of how you developed your design, in the event that another party later claims to have invented it first. A notebook with detailed notes and signed, dated witness entries that are organized chronologically is one common way to record the research and development process.