For those who airbrush designs onto cars and bikes, learning how to airbrush skulls is a must. Next to flames, skulls are the most requested type of airbrush design. They require attention to detail--painting any portion of the human body has long been one of the most difficult forms of art. It is often recommended that those wishing to airbrush skulls study a book on human anatomy, or at least a plastic skull.

The combination of the relatively high difficulty level and the widespread popularity of airbrush skulls has led to a wealth of instructional materials. Popular skull artists include Robert Benedict and Cross-Eyed, both of whom have instructional DVDs on how to create life-like skulls. Skulls require a blend of crisp lines and smooth textures. Often, artists will complete a skull design in layers, allowing them to devote each layer entirely to one style of painting.

Other than the female figure, no other design stymies artists more than the skull. Frequently, artists find it impossible to airbrush skulls without an extensive diagram. In addition to the curves and textures, an airbrush artist must also pay attention to shadows and lighting. Painting realistic shadows can make the difference between a "ho-hum" skull and one that stands out as realistic and unique.

Those who master skulls should also master fire. A large percentage of customers who want a skull on their vehicle or helmet also want flames to accompany the primary image. Naturally, the back of the skull is the most popular place for flames, but many artists choose to express themselves differently. Flames that seem to shoot out of a skull's ears can create a surreal, angry effect. Many artists choose to experiment with several combinations and include multiple looks in their airbrush galleries.