Two in one thinner and extender medium!!! In principle Revell Aqua Color paints can be diluted with water to facilitate spraying. However dilution with Aqua Color Mix has two advantages. Firstly, it is a retardant which prevents the paint from drying too quickly in the spray gun and on the background. Secondly, the thinner gives an improved result when sprayed on the model. When matt and satin matt paints are used Aqua Color Mix reduces undesirable lines when the paint is applied. Recommended mixing ratio: 3-4 parts paint to 1 part Aqua Color Mix. As this mixing ratio depends heavily on the spray gun used and the working pressure of the compressor, please test the paint with less thinner to start with. If the airbrush "sputters" or the paint dries too quickly on the model (rough surface) simply dilute it a bit more.