The invention relates to a plastic-based composite product which consists at least partially of a plastic in which a material consisting substantially of particles is homogeneously embedded, which particles have tensile strength in at least one principal direction. The invention provides a product of the stated type which has the special feature that the particles comprise: small particles, in particular plates or fibres, with a random orientation and a length of 0.2-2 mm; and large particles with a dominant orientation, for instance 80-95%, of the said principal direction of the particles in a chosen product principal direction and a length in the particle principal direction of about 2-6 mm.