Confectioners’ or powdered sugar (also often called 10X)

This is simply granulated sugar that has been ground into a powder, sifted, and lightened with about 3 percent cornstarch to prevent caking. It is available in different grades, each ground to differing degrees of fineness. That labeled 12X (also known as fondant or icing sugar) is the finest, 10X (generically called powdered sugar) is less fine, and 4X is even coarser. The type generally available in supermarkets for home use is 10X. The other two are used in commercial applications. Confectioners’ sugar is often sifted before being used in icings and confectionery and to sweeten heavy cream that will be whipped. It is called icing sugar in the United Kingdom and sucre glace in France.