Oak Bark Tannin  

 

ok, oak bark is used in making the oak bark tannin in a brewing barrel. its a very simple recipe; 1 oak bark+ 1 flask of water=1 oak bark tannin
the main recipe ive discovered for using this in is for the blessed faydark bows, which you need ; 1 oak bark tannin+ 1 small brick of mithryl+ 1 silk string= 1 light mithryl string.
hope this helps some :)