A method of producing a core board suitable for a coated multi-ply wood panel, as well as a coated multi-ply wood panel. The method comprises the steps of providing a wood based material in the form of a plurality of layers and an adhesive suitable for bonding the layers to each other; the layers of the wood based material and the adhesive being arranged in alternating order to form a stack, the stack having two opposite faces formed by a wood based layer. On at least one of the faces of the stack there is further provided adhesive and fibrillated fibers to form a modified stack which is pressed by one-step pressing to form a multi-ply wood panel having a facing coated with a layer of fibrillated fibers. The even and smooth surface of the core panel makes it particular suitable for coating with, e.g., glossy films.