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