Gamblin Galkyd Slow Dry Medium is formulated to have strength and flexibility and to keep the surface of oil paintings open for approximately three days. This is a good choice for those who blend or work wet into wet. Galkyd Slow Dry is fatter than Galkyd, so using large amounts may cause wrinkling. Use one part Galkyd Slow Dry and one part oil color for at least a day to paint wet into wet. Do not dilute.