What it means: Paint cup mounts on the side of the airbrush
A side-feed airbrush has its paint cup or bottle mounted on the side — either left or right — rather than on top (gravity feed) or below (siphon feed). The cup can typically be rotated between left and right positions to suit left- or right-handed artists, or to allow painting at extreme angles.
Side-feed designs are less common than gravity-feed but have specific advantages: the cup doesn’t block the line of sight as directly as a top-mounted cup, making precise detail placement easier, and the cup can be repositioned for awkward working angles.
Popular side-feed models include some Paasche and older Badger designs. The trade-off is slightly more complex maintenance and the need to position the cup at the correct angle to ensure paint feeds properly.
Related: Gravity Feed · Siphon Feed · Color Cup