Pay close attention to the color of the hair, of the skin you are shaving! The "blue" color, most use as a guage for depth, of how thin to shave, mostly only applies to skins with slightly darker hair. For the most part, the hair remains the same color, all the way to the root. Example: A chocolate fallow cape, will fall into that "blue", your looking for. A blonde fallow, wont have that blue skin color. You have to be able to judge your depth. A light colored hog cape, will also present the same problem. If you keep cutting, looking for blue, you are going to screw the pooch! Have a good one!