A method for generating a patterned light trapping structure on a planar surface of a multi-crystalline silicon wafer, the method comprising: transmitting a liquid mask material along a plurality of parallel elongated conduits wherein each of the conduits includes a capillary channel extending between a base portion and its tip portion such that a portion of said mask material is ejected from a tip portion of each said conduit, wherein the plurality of conduits are narrow and closely-spaced providing at least 394 conduits per cm (1000 conduits per inch); moving the multi-crystalline silicon wafer under the tip portions of the plurality of conduits such that the ejected mask material portions form a mask pattern on the planar surface of the multi-crystalline silicon wafer, wherein said mask material pattern is formed such that a portion of said planar surface is exposed through said mask material pattern; and etching the exposed planar surface portion such that the etched multi-crystalline silicon wafer forms the integral patterned light trapping structure wherein the plurality of conduits are attached to and extend from a printhead substrate, and the liquid mask material is transmitted to the plurality of conduits by supplying the liquid mask material into the plurality of capillary channel of a reservoir in the printhead substrate configured to feed mask material to the conduits such that the liquid mask material simultaneously flows from the base portion and along the body portion to the tip portion of each conduit such that the liquid mask material portions simultaneously flow along and are ejected from all the conduits, characterised in that the liquid mask material is heated as it is fed from the reservoir through a printhead substrate to the plurality of conduits by using a heated printhead manifold disposed adjacent to the reservoir so that a temperature gradient is created from the heated printhead manifold through the printhead substrate to the plurality of conduits, and wherein the liquid mask material is delivered to the conduits by controlling a viscosity gradient of said liquid material delivered to said plurality of conduits through heating of the printhead substrate adjacent to the reservoir so that the heating is controlled by creating a thermal gradient from a back of a printhead manifold. transmitting a liquid mask material along a plurality of parallel elongated conduits wherein each of the conduits includes a capillary channel extending between a base portion and its tip portion such that a portion of said mask material is ejected from a tip portion of each said conduit, wherein the plurality of conduits are narrow and closely-spaced providing at least 394 conduits per cm (1000 conduits per inch); moving the multi-crystalline silicon wafer under the tip portions of the plurality of conduits such that the ejected mask material portions form a mask pattern on the planar surface of the multi-crystalline silicon wafer, wherein said mask material pattern is formed such that a portion of said planar surface is exposed through said mask material pattern; and etching the exposed planar surface portion such that the etched multi-crystalline silicon wafer forms the integral patterned light trapping structure wherein the plurality of conduits are attached to and extend from a printhead substrate, and the liquid mask material is transmitted to the plurality of conduits by supplying the liquid mask material into the plurality of capillary channel of a reservoir in the printhead substrate configured to feed mask material to the conduits such that the liquid mask material simultaneously flows from the base portion and along the body portion to the tip portion of each conduit such that the liquid mask material portions simultaneously flow along and are ejected from all the conduits, characterised in that the liquid mask material is heated as it is fed from the reservoir through a printhead substrate to the plurality of conduits by using a heated printhead manifold disposed adjacent to the reservoir so that a temperature gradient is created from the heated printhead manifold through the printhead substrate to the plurality of conduits, and wherein the liquid mask material is delivered to the conduits by controlling a viscosity gradient of said liquid material delivered to said plurality of conduits through heating of the printhead substrate adjacent to the reservoir so that the heating is controlled by creating a thermal gradient from a back of a printhead manifold.