TrueCut rulers come with the TrueCut Ruler Track, a raised edge that interlocks with the Cutter Guide, giving you straight and precise cuts. These clear rulers have built-in slots for marking your fabric through your ruler! Mark seams and other fabric marks with precision. Built-in Ruler Track. Marked 1⁄8″ increments. Labeled 30, 45 and 60 degree angles. Built-in marking holes. Easy to see colours.