A clear, viscous solution formed when casein powder is soaked in water with an alkali (ammonium carbonate, borax, lime, etc.). The alkali hydrolyses the casein to make a solution that is usually stable for several weeks. Occasionally a plasticizer, such as glycerol or sorbitol and a preservative, such as phenol, are added to the solution. Casein glues since ancient times as a water-proof adhesive. Lime-casein glues were first patented in the mid 19th century. They were an important commercial glue through W.W.I for applications such as plywood. Casein glues were mostly replaced by phenolic, resorcinol and urea-formaldehyde adhesives in the 1930's and 40's. Synonyms: casein glue; ammonium casein; borax casein; lime-casein; lime casein. Museum of Fine Arts, Boston (2000). [J. Cassar, R. de Angelis]