Birchwood Casey's Perma Blue has been the pro's choice for years in touching up nicks and scratches. Easy to use, just clean the metal surface and apply. Birchwood Casey recommends using the Cleaner-Degreaser for cleaning the metal before application. Notes:Used to touch-up or re-blue clean and rust free metal surfaces on firearmsReacts slower than liquid blue formula, but lasts longerCan be applied with swabs (Q-Tips). No heat required