Life Color

I have found that if I thin it with the same Thinner I use when I Air Brush Poly Scale, it air brushes well.

 What I use for my Poly Scale Thinner is Distilled water with Liquitex Flow Aid.   I using a mixture of 30% Thinner to 70% paint.

The finish looks good, have not tried to mask it yet, we shall see.

I have used distilled water and it works fine. This is for hand brushing.Never tried it for airbrushing.

 For airbrushing I use a "airbrush medium" made by Golden or Liquitex... not too much as Lifecolor is pretty thin right out of the bottle.

Steve J

I am not real familiar with Life Color Acrylics Kirk,,,,  but, considering they are acrylic based, you might be able to use a similar (acrylic) thinner.

Experiment first,,, of course

Best of luck