Birchwood Perma Blue Liquid Gun Blue is the best way 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). Perma Blue will not blue stainless steel, aluminum or non-ferrous metals.Specifications and Features: Touches-up scratches and worn spots Completely reblues most guns Gives a streak-free, blued finish to steel 3 oz