problems? Will all damascus blade stain when used? How about stainless damascus from Devin Thomas or others ? I am thinking of getting a damascus folder as an edc, any suggestions?
Even plain carbon steel won't rust if you care for it properly.
Even the best "stainless" steel will rust if you don't care for it.
Carbon steel will just need more care. You'll have to clean it immediately after use and protect it with oil.
Use a good gun oil for working knives, and mineral oil if you intend to use it also to prepare or cut food.
After cutting food, especially meat or tomatoes, a carbon knife can get some blackish stain, but it's just part of the use of the knife and can be easily removed with flitz or car body paste or equivalent.
Don't do it on damascus, though, as it will make the pattern less visible.
Anyway it won't rust if properly cared for.
Even stainless must be cleaned immediately after use with food, or it will discolor or stain.