Alumicolor™ Triangular Drafting Scales are made of extruded aluminum. Alumicolor's™ photo anodizing process makes the calibrations a part of the aluminum, providing a smooth, tick-free finish and markings which are resistant to cleaners and solvents. Solid Scales have an executive weight and feel, and are widely used by drafting professionals. Calibrations: 10, 20, 30, 40, 50, 60 parts per inch. Size: 12" Engineer. Color: Gold.