PAINT DRYING RETARDER
As its name suggests, the Retarder is designed to slow down paint drying time.
This medium can be employed in two distinct ways. The first approach involves adding up to 3% of Retarder to your paint; this results in a slightly more fluid colour that remains wet for an extended period. Alternatively, you can place the Retarder in a hand-pumped spray bottle (atomiser) and mist it onto the artwork you want to keep wet. (The spray bottle should produce a fine mist, not a forceful squirt).
Adding a Retarder to your mixing water can benefit techniques such as watercolour painting, water wash effects, stain painting, and hard edge methods. It facilitates better pigment wetting, rapid colour diffusion, and deeper penetration.