Abstract: The invention relates to imaging elements comprising a back surface wherein said back surface has a low frequency roughness component having a roughness average of between 0.30 and 2.00 .mu.m when measured with a low pass cutoff filter of 500 cycles/mm and a high frequency component having a roughness average of 0.001 to 0.05 .mu.m when measured with a high pass cutoff filter of 500 cycles/mm.

Abstract: An improved extrusion-slide coating hopper for multi-layer coating of a substrate is described. The improved extrusion-slide coating hopper includes an upturned generally horizontally directed lip, which lip extends at an obtuse angle from an inclined slide surface and toward the substrate to be coated. A coating composition may be made to flow down the inclined slide and then upon the generally horizontally directed lip before being introduced on top of an extruded bridge of coating composition. The bridge of coating composition spans a generally horizontal gap between the hopper and the upwardly moving substrate. The apparatus of the invention improves upon coating apparatus of the prior art by providing, when coating, increased bridge stability and minimization of the deleterious effects of particles that lodge at an edge of the hopper.