Abstract: A method for changing the width of particle thickness size distribution of flakes of material with the flakes being formed by a process that includes the steps of feeding a stream of molten material in a downwards direction into a rotating cup or disc and allowing the material to pass over the edge of the cup or disc in such a manner as to be forced into a gap between a pair of plates surrounding the cup or disc. The movement of material in the process used for forming the flakes is maintained in an angular direction and effected by a flow of air passing through the plates and either side of the material, so as to pull the stream of material in a manner for keeping it flat and, further, to pull the stream of material so that, as solidification of the material is effected, the sheet of material so formed is broken into flakes.