What is stone resin? Solid surface, also known as stone resin, is a solid and non-porous material usually composed of a combination of acrylic resin, bauxite, epoxy, marble dust and pigments. Lusso Stone solid surface material is composed of 40% pure acrylic resin (MMA), 55% natural mineral (ATH: Alumina Trihydrate) and 5% colour pigment. Solid surface is used to mimic the appearance of naturally occurring materials such as granite, marble and stone and can be joined almost invisibly by a trained craftsman. This solid surface can then be cast into a variety of shapes, including our signature bathtubs, basins and shower panels.