Solid core acrylic. The material is flat, not porous, homogen both unicolour or granite surfeces. Kerrock is glued with Kerrock colour glue making all joints invisible. Forming of this material can be done the same way as wood or soft metals or can be heat formed as well. Kerrock has the strength of stone and the beauty of china. It is very durable has a lot of colours and can be used in million different ways.