Abstract: A gypsum board panel having two facing main surfaces and machine edge surfaces, the board including an outer gypsum layer in which a polymer additive has been entrained, and the machine edges being shaped to have a three-dimensional feature, such that the features are complementary, and one machine edge surface can engage the complementary surface of the machine edge of an adjacent gypsum board panel. The three-dimensional features may include a triangular, in cross-section, ridge, or a rectangular ledge, or a concave edge, with a corresponding complementary groove or depression on the opposed edge for engagement with the edge of an adjacent board.