Birchwood casey offers you the best ways to touch up scratches and worn spots or even completely reblue most guns. it will give a non-streaky, even blue-black finish to steel (except stainless). both Perma Blue liquid gun blue and paste gun blue provide great blueing to metal that has already been thoroughly cleaned and is free of rust. Features: The proven way for touching up or completely reblueing most guns Best way to touch up scratches and worn spots Non-sticky, even blue-black finish