M1rror Edge Sharpening Service often sees severely damaged Japanese knives while servicing our customer's tools (See Video). Significant chipping along the edge is the type of damage usually observed. This damage is typically a result of the steel's hard tempering, making it very brittle but hard on the very edge. The "chipping" found is preventable. Japanese knives will stay sharp much longer than standard European tempered blades; however, they do not hold up to abuse observed in the typical American residential kitchen. Japanese knives used on a soft cutting board will reduce or eliminate any "chipping" observed. Owners should use the knives, dry them, and then protect the blade edge before being put away. Using edge covers is recommended when not in use. In Japan, they call these sheaths "Saya." Modern plastic covers are enough for most users.