A process for the preparation of a prepreg comprising superimposing layer of unidirectional fibrous reinforcement comprising a plurality of tows each comprising a plurality of parallel filaments onto a resin impregnated layer of unidirectional fibrous reinforcement comprising a plurality of tows each comprising a plurality of parallel filaments wherein the superimposed laminate of layers is compressed to the extent that the resin penetrates the interstices between the tows but penetrates the voids within the tows to less than 22 to 60% by volume of the tows.