Charles Gillis has 30 years of mechanical design experience, previously serving as a machine design engineer for The Gillette Company. He has been training engineers in blueprint reading, geometric dimensioning & tolerancing, and related topics for 15 years. He is also a contributing author to the renowned Machinery's Handbook, 32nd edition, as well as the Machine Designer's Reference, both published by Industrial Press.

Warren Hammer (deceased) had more than 50 years of experience in manufacturing. He originated the Blueprint Reading Basics book, and with this latest revision, his legacy continues to live on.