This article analyses the active ingredient of glue paste (a mixture of cereal flour and animal glue) as well as the specific role of certain additives such as honey, molasses, flaxseed mucilage, and ox gall. The findings of the tests are unexpected in light of previous knowledge. The conclusions are that wheat gluten (a protein that combines with water to create an elastic web that is partially degraded during curing) is a texturing agent of fresh adhesive that makes it homogenous and unctuous enough to allow for regular application. Its three-dimensional web structure also increases the cohesion of the dry film. Rye flour contains a natural mucilage (pentosan) that has the same characteristics as honey, molasses, and flaxseed mucilage. Mistakenly used for a long time as softeners for dry film, they are actually humectants and act as water-retention agents. They reduce the deterioration of starch, slowing the drying process. The addition of ox gall, rich in surface-acting agents, does not increase the bonding, but does reduce the rigidity of the film. There is good reason for empiricism here, but such reasoning does not explain the results.