Alvin - Transparent Edge T-Square - 18 inch - The Alvin Transparent Edge T-Square features a selected hardwood blade for strength and straightness. Elevated, see-through acrylic edges for smudge-free line work. Smooth wood head attached with five screws for long-lasting squareness. 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.