A coating apparatus for controlling processing medium on and in non-woven rollers and on material adapted to pass through rollers is disclosed. The apparatus comprises a pair of non-woven rollers having generally parallel axes and having a porous, generally cylindrical outer surface. The rollers receive and absorb processing medium and have a portion of their adjacent outer surfaces through which material passes in pressure engagement whereby in the regions of the gaps where the rollers engage each other or the material passing therethrough, the processing medium will be of a generally uniform thickness. The rollers have gaps in regions along the edges of the material when the non-woven material passes therethrough. The non-woven rollers will pick-up and carry an excess amount of the medium in the regions to produce a wet edge condition. The apparatus further comprises preconditioning rollers disposed adjacent and generally parallel to at least one of the non-woven rollers and in generally uniform pressure engagement with the rollers to squeeze the non-woven rollers at least across the width of the non-woven roller beyond the edges of the material adapted to be processed therethrough whereby the processing medium will be uniform across the surface of the non-woven roller at least in the area through which the material adapted to be processed passes.