how do u keep airbrush paint from washing off a black shirt?

Answer 1

turn it inside out when you wash it.

Answer 2

You do not mention what kind of paint you are using - airbrush can apply acrylics, water colors, oil paints, etc. so that each has different characteristics....
If you are talking about hardened paints that are waterproof to start off with, then some of the suggestions of wahing inside out have some merit -- however, you do not even state what " washing" is.
Are you throwing the shirt in the dry cleaning? the laundry machine with bleached whites? gently washing it in mild soap and gently laying it out to dry ? wearing it in the swimming pool or in the water at the beach all day in the sun?
You could, as well as washing it carefully by hand in luke warm water by hand and LAYING it out on a towel to dry,
spray on a flexible clear coating of plastic, waterproof paint, on the outside, and on the inside. This would help bind the paint together, for a longer time. Note that you would have to use a flat paint if the airbrush paint is already faint and flat. If the airbrush is heavy and shiny, you can use a shiny coat. Another alternative is to use a shiny, flexible, clear plastic coat, and then coat that with a matt coat spray to dull the surface.
I would suggest, that whatever clearcoat you attempt, you TEST it on an area first, to see how it reacts with other paint and how it reacts to being washed. There are too many different products on the shelf to be certain which one will work best...
On the INSIDE of the shirt, you can use whatever kind of paint you want since no one can see it - just be aware though, that there may be some colour bleed through to the front if it is not clear paint.

good luck

Answer 3

Your best bet is to use acrylic paint and heat set it. This can be done with a commercial hand held dryer (or even a home hair dryer although this does not get as hot as the commercial ones do.) Or you can wait until the paint is set well then put it in your clothes dryer on as hot a setting as you have.

Over time any image will fade, but then the black on your shirt will also fade with time.

Answer 4

Iron it after the paint has dried

Answer 5

use acrylics or dyes