Alvin - Gemstone Template - set of two - The Alvin Gemstone Template is a set of two that contains 278 sizes, marquise, triangle, square, heart, round, oval, pear, and rectangle shapes. The Gemstone Template sizes range from 3mm to 15mm. Size: 6-7?16 inches x 9-7?8 inches x .020 inches. Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.