Alvin - Mechanical Draftsman Scale - 12 inch - Alvin 12 Inch triangular draftsman scales are ideal for scholastic and vocational use. These Architectural Scales have a satin finished, high-impact plastic with tapered edges. Sharp, easy-to-read graduations resist wear. 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.