This Engineer Stamp of Seal is a self-inking stamp and one of our most popular seal choices. Stamp pads can be changed quickly or re-inked for thousands of more quality rubber stamp impressions. The professional engineer stamp will make about 5,000 stamp impressions and is available in 11 ink choices. All engineering stamps are made to your state specifications and can vary from 1-5/8" in diameter to a 2-inch diameter impression area.