All steel benefits from some protection in long-term storage. Never store a knife long-term in a leather sheath. Even sheaths that are 'vegetable tanned' leather contain salts & chemicals detrimental to blades in the long run. Wipe down with a lightly oiled cloth, some guys like to use Renaisance Wax, some guys say a good paste wax is just as good, other knife specific products are available. Wood, stag & bone handles can all benefit from a good paste wax. If you collect any older celluloid handled knifes, keep them separate from your other knives, some older, poorly made celluloid can cause a chemical reaction with some steels as they degrade. Long term storage of automatic knives should be with the blades opened. There are a lot of good knife forums out there if you have more than a passing interest. Check them every six months - or at least yearly. If you handle or touch a blade with your fingers, always wipe it down afterwards -- IF you are at a show - REFRAIN from touching the blades on display -- you can handle the knife - just don't touch the blades - it will earn you some respect from the seller.