I'm preparing to make a cake for my graduating class, pretty big deal for my small town grad! But, I'm ordering Satin Ice fondant and wondering how much I should buy to cover a 3 tier cake, each tier 4 inch high and measurements of 12'', 9'', and 6''. Please help!!! Wondering if 10 lbs would be sufficient?

According to the Satin Ice web site:
http://www.satinfinefoods.com/product.htm

Cake Diameter Net Weight
6"................................................10 oz.
8"................................................12 oz.
10"..............................................18 oz.
12"..............................................24 oz.
14"..............................................48 oz.