There is a reason craft paints are cheaper than model paints. The pigments are not as finely ground, and color matching is often inconsistent between batches. They often dilute poorly as well. I use craft paints for backgrounds, landscape and base layers and places where it doesn't show as much. Models and figures always get the good stuff on my layout.
Connecticut Valley Railroad -- A Branch of the New York, New Haven, And Hartford
"We don't stop playing because we grow old. We grow old because we stop playing." --George Bernard Shaw