This material is made of casein proteins and looks almost identical to natural tortoise shell. It is ideal for restoration work, inlays and jewellery. The material is easy to process and feels extremely supple. Like other natural materials (wood, ivory), the casein surfaces should not be exposed to constant wet conditions. For glueing we recommend a Cross Linking PVA - see HERE. To bring the best out of glued imitation tortoise shell, the transparent sheets are often backed with coloured paper. This emphasises the colour and hides the background grain pattern.