The extract is cooked to form a gelatin material. The gelatin can then be reliquified with heat, which gives it quick setting properties. It s major use has been in the wood and furniture industry. If you have seen a heated glue pot with a brush in it, it was probably an animal glue. Animal by-products from meat processing have been the source of supply for this type of glue.
Fish glue is a similar protein-based glue made from the skins and bones of fish.
An exceptionally clear adhesive can be made from fish and was the first adhesive used for photographic emulsions for photo film and photo resist coatings for photoengraving processes. Casein glue is made from a protein isolated from milk. The extraction process creates an adhesive that is waterproof. Its first use was in bonding the seam of cigarette paper. It provides a fast setting bond that requires very little adhesive, one gram of adhesive can bond 2000 cigarettes.