White all-use glues like Elmer’s are made of rubbery mixtures called polyvinyl acetate emulsions, and while the Elmer’s mascot is a smiling bull, the company says that it doesn’t use any animal parts. Over the second half of the 20 th century, synthetic glues have become more advanced, as they are cheap, uniform in quality, and have longer shelf lives. Glue made from blood, which worked because of blood’s coagulative properties, worked particularly well when bonding plywood, and was commonly used for this purpose until the mid-20 th century.Īnimal glue, popular for thousands of years, has fallen out of fashion in recent decades. For fish glue, Theophilus recommended the bladder of the sturgeon, but alternatives included eel skin and “the bones of the head of the wolf fish.” The first commercial glue factory, started in Holland in the early 18 th century, used animal hides. In the middle ages, the mysterious author Theophilus compiled instructions for producing various types of glue, including glue made of skins and stag-horns, glue made from fish bladders (now called isinglass), and “ the glue of cheese” (now called casein glue). Other adhesives were made from egg whites, tree sap, tar, and beeswax, which the ancient Romans used to caulk the planking in ships. It wasn’t long before these animal glues were used to repair broken pots and, in one instance, glue ivory eyeballs into statues’ eye sockets. The oldest glue discovered was a collagen-based adhesive that was 8,000 years old and used to hold utensils together. Humans have used animals to make glue for thousands of years.

The glue