Anodized Aluminum Blanks 160 x 25 x 5mm are used for lapping films and stropping pads on guided knife sharpeners that work with 6" sharpening stones. Blanks are made of high-quality 5mm-thick aluminum with 45-degree bevels (Edge Pro form-factor) and color anodizing. Blanks are available in six colors: graphite gray, black, deep ruby red, ocean blue, emerald green, sepia orange. When stropping or lapping has more than one step, blank identification can be a headache. Different colors of blanks will help to avoid mistakes of using wrong grit.