A proven glazing putty for wood sash that has been around for decades. It is the superior vegetable oil based (soybean and linseed oil) compound. This is the best production putty available. Type "M" is a quick skinning product, usually forming a strong enough surface skin to be painted in 3-5 days depending on temperature. Type "M" is for inside shop glazing only. Packaged in a convenient quart or gallon sized bucket with resealable lid.