New Silver, Gold and White Cake S.O.S Solid Cake Boards are very strong, durable and the same time flexible. Round Boards are with thickness from 2-3 millimeters and rectangle boards are 3 mm. each cake board. Both sides are food safety, you can use gold/white/silver or black sides, it depends on you. Food-grade gold finish. They are perfect for supporting tiered cakes or using under cakes.