I am in possesion of a fair number of tubes of acrylic paint that I bought for an art class awhile back. These paints were not cheap, costing between $7-14 per tube (M. Graham & Co). I tried using them on my Phantom and Firespray and was pleased with the results (although I failed to thin the paint sufficently for the Firespray). Still, I find myself hesitating to paint more out of fear that it is the wrong type of paint. Is there any fundamental difference in the formulation of art paint and model paint or are they effectively the same?

The pigments in model paints tend to be far finer, and they tend to take watering down to the amounts needed far better then most "art" paints. They're made for different scales on the chemical level.

If the Graham and Browne paints are acrylic they should be fine. I used to use them on citadel

miniatures but they had to be thinned down and they ended up

with a very textured look-they looked 'painted' for want of a better word. I switched to citadel

paints which have a better consistency for models (though I am yet to try them on x wing minis). Whatever works!

You should be able to dilute the paints down, but as said, some tend to weaken the strength of the pigment at the same time. Best bet is to squeeze some out into a small pot/palette and dilute it slowly until you get the desired result, or decide that the paint can't be thinned down enough and still provide a good coat of paint. I recommend using some form of eye dropper to measure out the water/thinner. That way you can more easily remember how may drops of it you need when thinning down the paint.

After you think it's thinned down enough, either pick something that's textured enough, like a piece of textured card, or a 'sacrificial' miniature, and try painting it. If it's too thick/thin, try again.

Ok, sounds like it may be wise for me to pick up some mini paints. I don't care for the painted look that my Firespray has and I'd rather not be constantly fighting to get my paint thin enough. Thanks.

The paints are different and will behave and wear differently. Model paints will be harder wearing as they are designed for use on miniatures that get handled regularly. I wouldn't continue with the art paints.