Resurrection whetstone has two grooves (surface) and a flat surface (back), but both sides can be used. The surface of the grinding surface may be slightly finer when sharpened. First, apply water to the entire surface of the grinding. Hold the rebirth whetstone in your hand and draw a small circle without applying too much force to sharpen the entire grinding surface. No need to shave for a long time. If you peel one peel, the whetstone will restore its original performance.