Even though you take care of your knives, good knives need professional care. That kind of care can keep the knives straight and the blades properly angled. Using appropriately “gritted” stones, Masaya gives your knives the optimal edge. There is a wide range of grit “fineness” (graded from the 100’s up to 30,000). The higher the grit-grade, the finer the stone with which knives are sharpened. Usually a machine-sharpened tool uses the lower grade (between 140 to 200), and it takes only a few minutes to sharpen the knives. But the blade’s condition is not optimal with this process. The blade’s cutting ability is less-than-perfect. On the other hand, a blade manually sharpened with a finer grade of grit stone (graded over 1000) is not only very sharp but also very smooth. Proper care with refined grit stones requires time, at least 30 minutes per sharpening, but it enhances the longevity of the knives.