Damascus steel blades, no matter their origin will contain at least one or two High Carbon Steels Forged together with High Nickel Steels. The contrasting material when finished produce the beautiful layered appearance.
Once a blade has been ground and heat treated they are dipped in a bath of Ferric Chloride, which is and acid that etches the carbon steel and creates the detail. There are many alternate ways used to etch, but none that create as much detail.
All knives finished by 3H MFG receive a coat of Urethane Clear to maintain finish until delivered to customer. This coating can easily be removed. Using products like Rem oil and Barricade corrosion preventive compound will also protect finish.
If knife comes in contact with moisture it must be dried, cleaned and oiled. A product like Barricade will displace moisture and provide a protective coating.
If you do allow corrosion to mar the original finish you can somewhat restore the finish by removing corrosion with Steel Wool, Scotch Brite Or Fine Sandpaper. Then soak blade in White Vinegar for about 10 minutes. Then wash blade with soap and water. Dry thoroughly and spray with water displacing corrosion preventive.