A method of converting universal master boards into flush door skins having different assortments of simulated wood grain patterns, the method comprising: providing a plurality of universal master boards each having an expansive surface, each expansive surface having a graphic design of at least first depressions and second depressions in at least first and second surface regions, respectively, the first depressions being substantially parallel to one another and substantially aligned in a first direction to simulate a first wood grain pattern in the first surface region, the second depressions being substantially parallel to one another and substantially aligned in a second direction that is different than the first direction to simulate a second wood grain pattern in the second surface region, the plurality of universal master boards including at least first and second universal master boards; cutting the first universal master board at a first location to form a first flush door skin having a first exterior surface with a first assortment of simulated wood grains comprising at least one pattern selected from the group consisting of the simulated first wood grain pattern and the simulated second wood grain pattern and a flat interior surface; and cutting the second universal master board at a second location which does not correspond to the first location to form a second flush door skin having a second exterior surface with a second assortment of simulated wood grains comprising at least one pattern selected from the group consisting of the simulated first wood grain pattern and the simulated second wood grain pattern and a flat interior surface, the second assortment of simulated wood grains differing from the first assortment of simulated wood grains, wherein the height of the universal master board is at least as great as the preselected height of the flush door skin. providing a plurality of universal master boards each having an expansive surface, each expansive surface having a graphic design of at least first depressions and second depressions in at least first and second surface regions, respectively, the first depressions being substantially parallel to one another and substantially aligned in a first direction to simulate a first wood grain pattern in the first surface region, the second depressions being substantially parallel to one another and substantially aligned in a second direction that is different than the first direction to simulate a second wood grain pattern in the second surface region, the plurality of universal master boards including at least first and second universal master boards; cutting the first universal master board at a first location to form a first flush door skin having a first exterior surface with a first assortment of simulated wood grains comprising at least one pattern selected from the group consisting of the simulated first wood grain pattern and the simulated second wood grain pattern and a flat interior surface; and cutting the second universal master board at a second location which does not correspond to the first location to form a second flush door skin having a second exterior surface with a second assortment of simulated wood grains comprising at least one pattern selected from the group consisting of the simulated first wood grain pattern and the simulated second wood grain pattern and a flat interior surface, the second assortment of simulated wood grains differing from the first assortment of simulated wood grains, wherein the height of the universal master board is at least as great as the preselected height of the flush door skin.