Abstract: A method of absorbing resin into part of a panel of particleboard to provide local strength increases in that part. The method comprises subjecting the part to an electric field, immersing the panel in the resin; and then resubjecting the panel to the electric field to cure the resin. A particleboard panel is also disclosed. The panel has a main body with a specific gravity in the range 0.2 to 0.5 but at least one area on its periphery has a specific gravity in the range 0.7 to 1.0. The one area is impregnated with a synthetic resin. The panel is particularly useful in door production as it is strong but cheap.