Add a small amount of retarder to paint on palette. Work wet-into-wet, blending edges before the surface skins over. Keep a light misting bottle nearby — a little water on the surface also extends working time.

Portrait and skin tones: Retarder is particularly useful for gradual colour transitions in portraiture. Mix into flesh tones and blend across the form before the paint locks.

Gradient washes: Apply a strip of light colour across the canvas. While wet, add the darker value and blend with a dry fan brush. Retarder gives the extra minutes needed to achieve a seamless transition.

Combined with Gloss Medium: Retarder + Gloss Medium creates smooth, blended gradients with a subtle sheen — similar in effect to oil glazing.