Abstract: There is provided a method of engraving a workpiece surface 14 by etching using a thin flexible support foil 18 which carries a dissolvable pattern 20 made of a dye opaque to light. The support foil 18 with the pattern bearing side is deposited on the workpiece surface 14 and the pattern 20 transferred to the workpiece 12, after which the support foil 18 is removed and the surface 14 treated with an etching agent. Prior to the deposition of the pattern 20, a photographic lacquer layer 16 is applied to the surface 14. The lacquer layer 16 is then exposed to light through the pattern 20, after which the exposed or unexposed regions of the lacquer layer 16 are removed and the regions not covered by the lacquer layer 16 are then subjected to etching.

Abstract: A method for preventing the degradation of a hydrophilic colloid solution for a silver halide photographic light-sensitive material of which the viscosity has been or is to be increased using an anionic polymer containing an acid group, which comprises incorporating into the hydrophilic colloid solution at least one compound represented by the formula (I): ##STR1## wherein R.sub. represents a hydrogen atom or an alkyl group; and R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.