Abstract: Wet pressed fiber board material of high resistance to bending is produced by preparing a layer of fiber from a water suspension of the fiber, said layer being de-watered and pressed to form a coherent flat sheet, wherein raw material is distributed over the surface of said layer in varying quantities and/or qualities in a manner such that the pressed board obtains strip-like surface portions which extend in at least one direction of the horizontal plane of the sheet, said strip-like surface portions having varying density and/or strength properties, whereby the finished board has a higher resistance to bending than a homogeneous sheet having substantially the same average density.