There's a medium that you can buy that allows you to turn any acrylic paint into fabric paint. I think it's called So-Soft. It's mixable with Plaid, Art Deco, Ceramcoat, etc. and let's you paint on fabric without it becoming really stiff. You might try something like that to add a few highlights/lowlights to your fabrics when creating your art quilt. Please practice on scraps first. Personally I prefer dry brushing very thin layers on until I get the look I want.