Comments about Grumbacher Cobalt Drier: I just started using this brand of drier. The one I used before you had to mix 3 different solutions together. The only thing I don't like you have to experiment to find how fast you want it to dry.
Grumbacher's 2-1/2-Ounce Cobalt Drier Artists Oil Medium (1417335657)
Grumbacher Cobalt Drier is the only siccative that has been scientifically proven to be the least harmful to use for fine art painting. Cobalt Drier speeds drying of oil colors and oil painting mediums.
Because it is extremely strong, Cobalt Drier should be used sparingly by applying it in drops. It should not be mixed directly into oil paints, but first mixed into an oil painting medium, which can then be added to the paint. Cobalt Drier should always be tested before using it in a painting.
Caution — Follow safety instructions carefully. Not suitable for use by children. Shipping restrictions apply to hazardous materials