I have been trying a plastic model acrylic paint that has been awful. It does not stick to plastic or even to the manufacturers primer. It is so fragile if I touch it after it dries it leaves fingerprints. The manufacturer says I MUST only use their thinner to activate the paint. In desperation I used Airbrush Thinning Reducer and Extender Base mixed with the paint and what a difference! Not only does the paint stick over bare plastic but, as a bonus leaves absolutely no brush marks after drying. This product clearly saved me from throwing out over $200 of paint.