This sugar paste icing is ideal for covering celebration cakes and sculpted cakes. Made in factory that handles nuts. HOW MUCH DO I NEED?. - For a 5" tall cake rolling to 2mm thick: for a cake 4" width: 250 g, 6" width: 400 g, 8" width: 500 g, 10" width: 750 g and a 12" width: 1 kg.