This is an excellent Liquid Cold Blue That has Earned it's spot on many work benches. It is a very simple product to use. (See Pic.#2 for instructions).  Surface preparation is important in any finishing process. I tend to use acetone for degreasing. Depending on the metal type I have had excellent results by warming the metal with a blow dryer. I've used everything from cotton, tooth picks and 0000 degreased steel wool for applying this blue.

It is wonderfully effective.

Have Fun.

Thanks Danny.