This Paderno World Cuisine "swirling staircase" polycarbonate chocolate mold is very sturdy. They create crisp edges and show detailed design. All molds are made of polycarbonate, a thick clear material that makes these molds thermal shock-resistant and easy to clean. All surfaces of the mold are perfectly smooth and glossy for a perfect finish. Polycarbonate is virtually unbreakable and will last a lifetime.