Spit bite is a technique related to aquatint used in intaglio printmaking, prized for its painterly appearance. A spit bite is produced using an intaglio plate—most often made of copper. The plate is prepared as an aquatint, by covering it with a fine, even coat of powdered rosin and baking this powder on. The rosin hardens into round particles evenly covering the plate. Rather than dipping this prepared plate into an acidic solution, as with an aquatint, the artist paints on the plate with a solution made of acid mixed with gum arabic, or, more traditionally, saliva. This solution “bites” into the exposed areas of metal around the rosin particles—hence the name “spit bite.” Saliva was originally used because the consistency allows it to stick to the metal plate’s surface. The artist may also drip or splatter the mixture onto the surface of the plate, producing somewhat unpredictable results. The darkness of the marks produced depends on the concentration of acid in the mixture. These many variables make spit bite very hard to control. The effect of spit bite is often compared to watercolor, and the washes of acid have an appearance distinct from the sharp, delineated images produced by other types of intaglio printing.

While some artists produce works using this technique alone, spit bite may also be used in combination with other intaglio methods. For example, Tony Cragg employed both spit bite and soft ground etching to make his Cannisters series. Chuck Close has created a number of prints using spit bite alone, including a self-portrait from 1988. His use of the medium is notable because he controlled the strength of his acid solutions to create many carefully calibrated shades of gray. Other artists who have used spit bite include Chris Burden, Mark Dion, Glenn Ligon, Jill Moser, Laura Owens, and Fred Wilson.