Custom Knife Care (Blades and Handles) By Rhonda Erline I own and sell custom made knives by Marvin Poole and I’ve learned good knife care is important to keep them looking and performing at their best. Whether you are a collector who likes to admire your knives for their sheer design and beauty or a person who uses the knife, taking proper care of your knife will ensure it will last many years to come. Knife Use Your knife was designed for a specific task and purpose. Do not use the knif.