I need a quick and CHEAP way to protect my kitchen knife and make it clearly different from all the other knives my housemate buys. She stores all her knives shoved together in a kitchen drawer, and is the sort who will grab the first knife she can get her hands on when needed without paying attention to whether it's her cheapie 'you can cut a sneaker with this' knife or my much better chefs knife. I was thinking of sewing a brightly coloured sleeve for it and storing it out of the way in a rarely used cabinet. My question though is about the material used for a sleeve. Is any one material better than another for knives? Cotton? Wool? Linen? I would hate to assume that all are fine only to discover that I've ended up damaging my knife as I really can't afford to replace it. I've got scraps of all fabrics and was just planning on making a padded sleeve to slide the knife into when it's not in use.
Alternatively, does anyone have any ideas for a DIY knife sleeve that can be made from items commonly found around the average crafter's home?