ESEE knives are made from high carbon 1095 steel. And while 1095 is a top choice for professional cutlery designed for hard use, it will rust and stain if not properly cared for - especially on the cutting edge and around the laser engraving. Keep the blades properly lubricated and cleaned. We suggest using a dry film rust inhibitor such as TUF-GLIDE or TUF-CLOTH.