Since its invention in the late 1800s, the airbrush has developed from a crude tool into a highly refined instrument. Today the airbrush is commonly used in a wide variety of ways, from painting, illustrating, and applying makeup to dying fabrics and tanning.

The airbrush is basically a miniature spray gun for applying just about any fluid medium. Artists of all kinds use airbrushes with paints, inks, dyes, makeup, watercolors, lacquers, varnishes, and even food coloring. Depending on shape and design, it can be used to cover large areas quickly and easily or to work with extreme control in a very small area.

The airbrush works by passing pressurized air over a paint reservoir. The paint is pulled up, atomized into very tiny droplets, and blown onto the surface being painted. The finer the atomization, the smoother the effect.

There are several choices to make when purchasing an airbrush:

Internal vs. External Mix—Air and paint can be mixed either inside or outside the airbrush. Internal mix airbrushes mix paint and air inside; they are able to produce a much smoother and finely atomized spray pattern. External mix airbrushes mix paint and air outside the airbrush; while their spray patterns are coarser than with an internal mix airbrush, they are much easier to maintain and clean.

Double vs. Single Action—Double action airbrushes allow the user to control both air and paint flow while spraying. This design gives more control over the spray pattern. Single action airbrushes only allow control of air flow while spraying; the amount of fluid sprayed can be pre-adjusted, but the flow remains constant at that amount.

Gravity vs. Siphon Feed—Most airbrushes use either a gravity or siphon feed. Gravity feed airbrushes mount their paint containers above the gun and let gravity pull the paint down into the brush. The advantage of gravity feed is that colors can be added a few drops at a time and changed easily and immediately. Siphon feed airbrushes mount their containers on either the side or below the gun. Mounting the reservoir below allows large bottles of color to be used, removing the hassle of constantly having to add color. Mounting the reservoir on the side allows the working surface to be clearly seen, an essential feature for creating fine detail.

Needle Size—Three general needle sizes are available: fine, medium, and heavy. Fine works best with thinner mediums such as watercolors, inks, and dyes. Medium is best for more viscous mediums such as oil and acrylic paint. Heavy works well for the thickest mediums like gesso and varnish. See Replacement Needles.

Other needs:

Cleaning—It is important to clean the airbrush after each use. Paints and other mediums can clog if left to dry in the gun. Cleaning is a simple procedure, however, usually done by spraying a solvent through the system. See Cleaning Products.

Compressors—Because airbrushes need pressurized air to work, an air compressor is usually required. The compressor should supply constant yet adjustable pressure for an even spray. Different airbrushes can operate at anywhere from 1 to 100 psi, so an appropriately powered compressor should be chosen to match the needs of the airbrush. See Airbrush Compressors.

Safety—Atomized mediums can often stay suspended in air after spraying, and because the droplets are so small, they can be inhaled into the lungs. For this reason, a respirator or mask should always be worn when operating an airbrush. See Safety Products.

Frisket and Templates—For creating intricate detail and fine line separation with an airbrush, frisket and templates are indispensable. They mask areas that you don't want painted and leave open the areas that you do. Great for beginners and those learning to use an airbrush, templates and frisket are also handy tools for professionals who need exacting detail in their work. See Friskets and Templates.