Alumicolor products are made from the highest quality tempered extruded aluminum. The extrusion process creates rulers and scales with smooth edges to exact specifications. The Alumicolor photo anodizing process makes the finish, the color and the calibrations a permanent part of the aluminum. Calibrations are resistant to cleaners or solvents. The anodizing process also means no ticks, raised surfaces or grooves to interfere with the creation of accurate plane, drawings and other precision work.