the stale air keeping ur knife inside the sheath long term will stain so u need to check and oil periodically.
due to nature of tight fit, some sheaths (esp. kydex) tend to scratch blade finishes, so if ur fixed blade is a collector piece, it wouldn't be a good idea to remove the knife in and out of the sheath too many times during its lifetime.
yes,, it is right,,never store knife in leather sheath..the leather has a lot of chemicals, acids, during its tanning process, and will harm the blade, even if stainless. if you are using a nylon shealth then it probably is ok, thats the trouble with fixed blade...need to unsheath to store it.. and it could be dangerous with a bare blade right in the drawer.
maybe one method is to use oil then put in a paper cardboard sheath..like when it is delivered to you when you bought it...
incidentally... Aogami Super Blue Steel which Spyderco is using...quoted from the spy site:"Hitachi creates and offers different grades of steels including white steels and blue steels. The steel isn't blue or white but the designation refers to the color of the paper the raw steel is wrapped in when delivered to Hitachi. It is common practice for Japanese steels to be named and referred to; based on what colored packaging the raw steel arrives to the maker. "
Now i wonder if the blue paper are wax or oiled paper?
any idea?