Some supplier's single thick cake cards are only 1.5mm thick, our single thick cake boards are 3mm thick which are akin to double thick. Manufactured in the UK from cardboard, covered in a lightly embossed food-approved foil with wrapped edges and white paper underside. Single thick card if rigid enough for smaller sponges, gateaux and cupcakes, though it will flex under weight and for larger (10"/30cm cakes) or delicately iced cakes we would recommend using 4mm card which is more rigid or cake drums which do not bend.