Clear Adhesive Tape: Rubber and Rosin Cement on a Clear Cellulose Film, Drew 1939

Richard Drew's clear tape (US 2,177,627, 1939): a clear cellulose film coated with a sticky rubber-and-rosin cement that stays tacky without water or heat. His Example E is 250 parts rubber to 160–200 parts rosin, dissolved, spread thin on the film, and dried. Here the film is celluloid, one of the cellulose esters he names. The picture: a roll of clear adhesive tape (photo by BarberJP, Wikimedia Commons, public domain).