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Mediums for Airbrush Technique

The Airbrushing Work Space

Overspray--The Airbrushers Friend and Foe

Overspray is an intrinsic result of spraying paint through an airbrush. For those new to the technique, this is the paint that drifts past the area to be painted. It appears as a soft mist that is sometimes so soft that you don't realize it exists until stencils or frisket are removed, and you see a ghost image of the outside edge of the stencil. When this happens, it can be disastrous to your artwork and sometimes difficult, if not impossible, to correct.

On a positive side, this drift of spray is what gives you the ability to develop a vignette (a change in value from dark to light) that can be used to create the look of volume, value changes, and mist or fog, among other effects. The airbrush artist learns how to capitalize on the positive effects of overspray while always being conscious of the negative. For instance, when you cut a circle in a stencil for a three-dimensional sphere, the overspray is utilized to give the shape dimension.

Several things determine the amount of overspray that is generated. One is the psi (air pressure) at which you are spraying. With higher air pressures, more overspray is produced. Another factor is the distance at which the airbrush is held from the work surface--the further away, the more overspray that will appear. As paint leaves the tip of the airbrush, it immediately begins to spread into a fan; and the longer it takes for the paint to reach the work surface, the wider the fan will be. A third factor is the size of the spray equipment being used--the finer the tip (such as that of an Iwata Micron airbrush), the less overspray; while the wider the tip (such as that of a spray gun), the more overspray. The worst-case scenario would be working at a very high air pressure with a large-tip airbrush at a distance far from the work. (This, of course, is an extreme situation.)

When even the smallest amount of fluid is sprayed to develop the finest of lines, a bit of overspray will drift onto the work surface. This is what makes a line appear to be somewhat out of focus when closely examined. If you wish to achieve a hard edge, you must use masking material such as frisket film, acetate or tape to prevent the overspray from drifting onto other areas. When the stencil material is removed, a hard edge will appear.

When working on a large scale, more overspray is produced and you must mask out larger areas. This can be done with Kraft paper, newspaper or masking paper that comes with an adhesive edge to keep it in place.

An important fact to consider in regard to overspray is that paint enters the environment of the artist's studio. Establish a system or use equipment to protect yourself from paint inhalation. Options can include wearing a dust mask or a respirator that fits over the nose and mouth to filter the air. Various respirators are available for different types of filtration. Some capture particles from the air, while others additionally capture fumes.

Adequate ventilation is also highly recommended and can be achieved by using a circulating fan or air cleaner, working in front of an exhaust, or installing an exhaust fan in a window. If the air is constantly circulating and being exhausted outside, you may choose to work without a respirator or dust mask, which some artists find bothersome. Another option includes spray booths that contain an exhaust system, which can range from homemade boxes with exhaust fans in the back to commercially designed spray booths available from small sized to those large enough for a car. (See www.artograph.com.)

Overspray is an inherent aspect of airbrush technique. However, once you become accustomed to how much is produced in a given situation, you can take preventive measures to insure a healthy work environment, while utilizing the spray effect to your advantage.