Grumbacher - Cobalt Drier
Cobalt Drier
Speed oil paint drying times without compromising color or texture
Oil paintings often need to dry between layers, and waiting days for each stage can stall momentum on a piece. Grumbacher Cobalt Drier accelerates the oxidation process that cures oil paint, reducing drying times so you can continue working sooner. Traditional cobalt formulation works reliably across different oil paint brands and pigments, though drying acceleration varies with paint thickness and environmental conditions.
Add sparingly, a few drops mixed thoroughly into your paint is typically sufficient. Excessive amounts can make paint brittle or cause cracking over time, so restraint matters more than generosity here. The 2.5-ounce bottle provides enough medium for extended use, since each application requires only small quantities. Particularly useful when working in layers that need to firm up before subsequent glazes or details, or when environmental humidity slows natural drying.
This medium addresses the practical reality that not every painting session can wait three days for the previous layer to cure. Mix it into your paint rather than applying it over dried layers, and always test on scrap canvas first when working with unfamiliar pigment combinations or techniques that demand specific drying characteristics.
