Our 4mm thick cake boards are manufactured in the UK from compressed, sterilised wood pulp, covered in a lightly embossed food-approved foil with wrapped edges and white paper underside. Designed primarily for larger sponge cakes, 4mm boards offer an alternative to cake drums and although much stiffer than single thick card, they do still have a slight flex - if in doubt it's better to get a cake drum which is rigid.