Airbrushes are also a commonly used tool for figure painting. An airbrush can be used to apply primer, either single color or zenithally, basecoats, and varnish quickly across large areas, as well as finer detail work such as creating color or value gradients and applying tints or glazes to large areas. For fine detail work smaller needle sizes are preferred, although larger needle sizes are preferred to speed up less detailed applications. Gravity-feed airbrushes are preferred over side- or bottom-feed as there is less paint wastage, and dual-action is often preferred over single-action as it provides greater spray control.