Use Liquitex Slow-Dri Medium to increase working time. This clear-drying Blending Fluid Medium is uniquely formulated for superior surface blending with acrylics. This Medium increases the "open " working time up to 40%. Dries clear to reveal full, rich color. Any quantity may be added to color without jeopardizing the strength of the paint film. Translucent when wet, transparent, flexible, non-yellowing and water resistant when dry. Size : 16oz.