Airbrush paints, like other paints, come in oil, acrylic, gouache, and water based formulas. However, airbrush paints differ from traditional paints in their viscosity. Airbrush paints have smaller ground color pigments that allow better flow through the airbrush. Gouache paints are mixed with white pigment to intensify opacity. This additional pigment can make it more difficult for the paint to flow through airbrushes.
Some airbrush paints are designed for body painting and temporary tattoos. These paints are alcohol based to extend the life of the temporary tattoo. There are also makeups that are prepared for airbrush application. As with other paints, you can also airbrush regular makeup, but you may need to thin the makeup. Choose makeups that don't settle quickly, even before thinning. Lumps in the bottle may indicate that the makeup will not flow easily through the airbrush.
Opacity in paints refers to the degree of translucence that will allow or inhibit light from passing through. Oil paints are translucent and slow drying. Acrylic paints are formulated in opaque and transparent. Watercolor paints are a wash paint. Gouache paints use concentrated white pigment to achieve maximum opacity. Heavy pigmentation can make paints thick and impede flow through airbrushes. You can thin paints manually to get the desired viscosity for use with airbrush application.
Thinning paint changes the viscosity to make it flow better through the airbrush, and to make for easier clean-up. You can use water or silicone for thinning makeup. Use distilled water to insure hard or soft water won't affect the paint. If available, use your paint brand's thinners, or reducers, for optimal compatibility. For oil based paints, turpentine and mineral spirits are options. Other thinners include acetone, true turpentine, toluene, white spirit and xylene.
Follow all handling instructions and warning labels for use and disposal of paints. Use a mask to protect yourself when working with airbrush paints and thinners. Work in proper ventilation with all paints and thinners to avoid being overcome by fumes. Since thinners and paints can be flammable, be sure to have on hand an appropriate fire extinguisher. Use paint thinners to clean your airbrush. Disassemble your airbrush before storing to remove paint and prevent build-up.