Alvin 110 series architects scale 12" has graduations 3/32, 3/16, 1/8, ¼, ½, 1, 3/8, ¾, 1 ½, 3” to the foot; with one edge calibrated to the 16ths. The most popular Alvin scaled ruler is made from satin-finished impact plastic with tapered edges and black easy-to-read printed graduations that won't rub off.