It is important to keep accurate records documenting your progress on your invention, starting with a written record of your idea even before doing any experimentation. Then make a complete written description, with drawings and photographs if appropriate, at all stages of your experimentation. Keep any correspondence about your work, sales receipts from materials, and any other records that might help you prove the facts and dates of your accomplishments. Get at least one trusted person who can understand your invention and corroborate your work to sign and date your written description of your project. Then sign the records yourself and affix the date. If another inventor should come up with "your invention" at about the same time, the records could be relied upon to establish who was the first inventor.

The U.S. Patent and Trademark Office also provides a service, called the Disclosure Document Program, that will establish evidence of the conception of your invention. Under the program, the U.S. Patent and Trademark Office will keep, for two years, the record of your invention pending the filing for a patent. The records will be destroyed after the two-year period if you fail to follow up. The fee for the service is payable to the Commissioner of Patents.

Remember, the Disclosure Document Program does not provide patent protection for your idea; it simply allows you to establish evidence of the dates of your invention. You must arrange for the filing of a patent application.

At this stage, you should be extremely secretive about your work. When in doubt-don't disclose information about your work. If you describe your invention in a printed publication, or if you use it publicly or place it on sale, you must apply for a patent within a year of the public disclosure. Otherwise, your right to patent the invention in the U.S. will be lost. Importantly, although you have a one-year grace period in the U.S. after public disclosure or sale, a public disclosure even one day before filing your patent application can bar the patent in foreign countries. No other country provides the grace period extended in the United States.