Virgin carbon produces the tightest grain structure possible in a steel. For this reason, it can produce a sharper edge than any stainless steel alloy. When used on meats, fish, and most produce, the edge retention is better than stainless steel. When used on acidic foods like citrus and tomato, the edge will break down faster. These knives WILL take on a patina (grey color) and WILL rust if not thoroughly washed and dried after each use. If rusting occurs, we recommend simply sponging the blade with "Bar Keepers Friend". This product is readily available at grocery and drug stores.