buy a gravity feed spray gun, hook it up to your Air Compressor with an air/water/oil separator then a regulate to 50-70 psi. 6-12 inches from cardboard, train using cheap house paint. thin it out and filter it into the reservoir. adjust knobs to spray desired pattern and disbursement. over spray by 50%. if you're craftsmanship doesn't meet desired quality... might want to either take into a shop, maaco is dirt cheap. but the best shops... minimum is maaco's highest.