A non-aqueous coating composition of very low volatility (i.e., low-VOC) that can be cured in a short period of time under an ambient temperature condition without the use of solvents consisting essentially of a mixture or blend of three components: (1) a complex ester made by reacting a monomeric monobasic fatty acid, a mixture of diacids and a polyol;(2) a drying oil (i.e., primarily an unsaturated fatty acid triglyceride); and (3) an unsaturated monomer of low volatility and its use for producing a coated substrate and especially a wood composite material substrate having a cured seal coat.