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 recommended for shop use (only use outdoors during a week without forecasted rain to allow curing time). Packaged in a convenient quart sized bucket with resealable lid.