The term resin indicates various translucent viscous materials, natural and synthetic.
Sculpture quite particularly was sensitive to the invention of resin to experiment it. Synthetic or semi-synthetic materials, the distinct materials that it adopted formed two large categories: Thermoplastic resins (cellulosic plastics, méthacryliques resins or polyméthacrylate of methyl, polyamides, polystyrene) and thermodurcissables resins (epoxide resins, resins polyurethanes, elastomers, phenol-formalin resin, casein-formaldehyde, polyester with styrene and the polybéton).
Unlike thermoplastic resins, thermodurcissables resins, once in shape, do not soften any more under heat effect; they are for the greater part insoluble, really hard, transparent and infusible. One can mix resins to modify their viscosity, their hardness or their flexibility.