It is known to use small, light weight mesh pieces having high flexural recovery, to strengthen a matrix. Such mesh pieces are very difficult to handle and package. In order to provide a suitable packaging system, mesh pieces 11 are deposited across the width of a moving run of flexible wrapping material 13 and are deposited in longitudinally overlapping relationship along the length of the wrapping material, by feeding the mesh pieces 11 on a belt 10 which moves more quickly than the wrapping material 13; the mesh pieces 11 are ejected from the end of the belt 10 onto the wrapping material 13. The direction of movement of the wrapping material 13 is inclined downwards so that the trailing ends of the mesh pieces 11 contact the wrapping material 13 before the leading ends contact the preceding mesh piece 11. The wrapping material 13, with the mesh pieces 11 on it, is then rolled up under tension into a spiral bale so that the overlapping edges curl down and prevent the mesh pieces 11 slipping out.