Mark Lee - Express Blue #1, 4 fluid ounce bottle for use on steel. Noted gunmaker and author John Bivins is quoted "Gunmakers, both centerfire and muzzleloader alike, have long needed a bluing solution which could be used with a minimum of amount of equipment, time, mess and hazard, which would produce a lustrous "true" blue. Traditional slow-rust blues have generally served this purpose, though they often requires much as twelve days to adequately finish steel parts. Lee's directions detail a more efficient method, which simply calls for heating the part with a propane torch until it will just dry the solution rapidly when it is swabbed on. Due to the fine grain oxide Mr. Lee's solution produces, parts should be hand -polished to at least a 400 grit finish." Mr. Lee notes that field use of his blue has shown to have excellent durability.