What it does: Controls paint flow by moving in and out of the nozzle
The needle is a tapered metal rod that runs through the length of the airbrush body. Its tip seats precisely inside the nozzle. When the trigger is pulled back (in a dual-action airbrush), the needle retracts slightly from the nozzle, opening a gap that allows paint to flow out. The further back the needle retracts, the more paint flows.
Needles are sized by their tip diameter, which corresponds to the nozzle size: 0.2mm, 0.3mm, 0.35mm, 0.4mm, and 0.5mm are the most common sizes. Finer needles (0.2–0.3mm) enable hairline detail but clog more easily with thick paint. Larger needles (0.4–0.5mm) handle heavier paints and provide more coverage.
Handle with care: Needle tips bend easily if the airbrush is dropped or the needle is mishandled during cleaning. Even slight bends cause spray problems. Always store the airbrush with the needle cap on.
Related: Nozzle · Dual-Action · Needle Cap · Trigger Control