This is a matt with several uses, but it is not permanent paint. It gives an " edge" to high-key subjects, controls small shadow or highlight areas, and reduces the "see through" in transparent objects.
The original favourite, for cutting flare on polished articles, now improved. Almost transparent, it can be used in colour photography without obscuring decorative designs. It is safe with most plastics. Used by museums on antiques, and in dentistry to reduce flare on polished instruments!
As the name suggests it gives a four times overall neutral cut, it can be sprayed on windows and transparent screens. Used extensivaly in the motion picture and television industries, it is an aid on small locations. Easily removed with a little methyl sprit.
Naturally an opposite to black! Reduces flare on shiny white foregrounds. Simple effects obtained on small backgrounds, used alone or with matt black.