Professional sharpening requires the use of different grits of whetstones. Using water whetstones allows the sharpening angles to meet at one and the same point, which makes the blades very smooth and sharp. Norton Waterstone water whetstones are professional tools that come in a plastic storage case with instructions for use. The intended use determines the grit of the stone. Grit 1000 sharpens the blade to a flat and smooth angle. It is the most common grit when sharpening new knives and removing factory marks. NOTE! WATER USED FOR GRINDING!