A computerized airbrush system with a full three dimensional airbrush interface is presented. The position and orientation of an electronic airbrush tool is tracked in space, and, when the trigger is pulled, paint is sprayed onto two and three dimensional objects displayed on a computer monitor. The experimentally derived paint spray model used for the airbrush takes into account factors such as air to paint ratio, viscosity, and distance of the airbrush from the work. Paint mixing between colors applied to the surface is modeled using Kubelka-Munk theory. Computerized stencils, including semi-permeable stencils, can be manually positioned by the artist or projected onto the object's surface. Two and three dimensional examples of traditional airbrush artwork, produced using the system, are presented. The system can also be used as a modeling tool to decorate three dimensional objects.