A board consisting at least of a substrate formed at least of a gypsum-based and/or cement-based basic material layer. The board is provided with a chamfer extending through the basic material layer.

A resin layer, having a generally planar form and having a first outer face and an essentially parallel second outer face, and supported on its first outer face by a supporting structure, parallel to and in contact with the first outer face, wherein the layer comprises a skeletal structure embedded within the resin, the skeletal structure comprising: a plurality of studs distributed throughout the plane of the layer, each stud having a length in the direction perpendicular to the plane of the layer, and terminating in a first end and a second end, the studs having a length extending from at least the first face to at least the second face; and a framework of solid connections, connecting each solid stud to a plurality of adjacent studs, particularly for use as part of a prepreg.

A board consisting at least of a substrate formed at least of a gypsum-based and/or cement-based basic material layer. The board is provided with a chamfer extending through the basic material layer.