Protect carbon steel knives with a light coating of hand-buffed wax, not oil. Oil attracts dust as well as weakens the sheath. Some carbon steel knife blades are blued. Nitrate bluing is a very thin patina that will wear away, leaving a gray metal finish. They are rust inhibitors, not rust preventatives.
Etching is used in the maker's mark and for some cosmetic enhancement.
Wood handles usually benefit from a light coating of furniture wax and a good hand rubbing. Brass and Nickel Silver fittings can be buffed and lightly waxed for protection. It is normal for some scuffing to show on the front bolster or guard, this is where the sheath holds the knife. Wrap your dry knife in plain paper, store with sheath and photographic quality desiccant in a plastic bag. Most accidents occur when dull knives are pushed too hard.