Designed for heavier celebration cakes and structures, a Cake Drum is the strongest and thickest type of cake board, being 12mm thick and comprising a bonded fibre board inner covered on the top and sides with fern embossed aluminium foil, with a white paper lined base. As a rule of thumb, decorators tend to use drum boards that are two inches bigger than the largest cake tier. For example, if you are baking a 12 inch cake, you will need a 14 inch drum board.