Abstract: There is provided a method of preparing a natural fibrous material particle composition such as a wood chip composition for use in forming a particle board which includes the steps of impregnating from 50 to 95% by weight of the composition of the particles with a compound selected from coal tar, pitch, asphalt and bitumen dissolved in a solvent therefor such as dichloromethane, applying from 2.5 to 25% by weight of the composition of a novolac resin including a cross-linking agent, in finely divided powder form, to the impregnated particles so that the resin adheres to the impregnated particles, and recovering the solvent. This composition may be used to manufacture a particle board in a platen press by coating the platens of the platen press with a layer of the novolac resin, and then placing the composition between the platnes and subjecting the composition to suitable conditions of temperature and pressure to cause the novolac resin to cross-link to form the board.