Amazon.com: U.S. Art Supply 4-Ounce Pint Airbrush Thinner for Reducing Airbrush Paint for All Acrylic Paints - Extender Base, Reducer to Thin Colors Improve Flow - Works for Thinning Acrylic Pouring Paint :
Airbrush Thinning Reducer and Extender Base, 1 Oz. Pint Bottle — TCP Global