Retarder is an additive mixed into paint to slow its drying time. For airbrushing, this is primarily useful to combat tip dry — the tendency of fast-drying acrylic paint to dry on the needle tip mid-session.
When to use retarder:
- Working in hot, dry, or windy conditions where paint dries rapidly.
- Using a very fine nozzle (0.2mm) where even minor tip dry causes blockage.
- Doing wet-into-wet blending on the surface.
Don’t overuse: Too much retarder can cause paint to remain tacky for hours, attract dust, and affect adhesion. A few drops per cup is usually sufficient. Flow improver is often a better first line of defense against tip dry; retarder is the stronger tool when flow improver isn’t enough.
Related: Tip Dry · Flow Improver · Reducer