Bone glue, pearls

Stronger than most modern adhesives, animal glues are still used in wood restoration and traditional woodworking, as well as in some painting techniques. Once thickened in water and heated in a water bath, they are used when hot and gel on cooling. In carpentry, their solubility in water makes them reversible, also allowing the rectification of the gluing. In painting, they are used both as a primer for canvases and boards and in the preparation of tempera paints and, of course, in the traditional techniques of gilding with glue. Animal glues are distinguished by their different degrees of adhesiveness and elasticity, but in any case, the tendency should be to prepare glues with the minimum concentration required, in order to avoid risks of traction or tensions in the glued materials.