It is recommended to apply the Primer in several layers. The product dries quickly and forms a uniform film of exceptional strength and support within a few hours of application. The Surface Primer can be used directly or diluted with Vallejo Airbrush Thinner or Flow Improver. The recommended compressor settings are around 15-20 PSI or 0.5 to 1 kg. For the best maintenance of the airbrush, it is recommended to use Vallejo Airbrush Cleaner.