Patent ID: 6852475

Claim:
A method for making a forming structure, the method comprising the steps of: a) providing a forming unit; b) providing a backing film; c) providing a foraminous element; d) juxtaposing the foraminous element and the backing film with respect to the forming unit so that the backing film is interposed between the foraminous element and the forming unit; e) providing a liquid photosensitive resin; f) applying a coating of the liquid photosensitive resin to the foraminous element; g) juxtaposing in contacting relationship with the coating of photosensitive resin a first mask comprising both opaque and transparent regions; h) controlling a first thickness between the backing film and the first mask of the coating to a preselected value; i) exposing the liquid photosensitive resin to light having an activating wavelength through the first mask thereby inducing partial curing of the photosensitive resin in those regions which are in register with the transparent regions of the first mask; j) removing the first mask; k) removing substantially all uncured resin; l) repeating steps (a)-(k) one time with a different, second mask replacing the first mask in steps (g)-(h) and a second thickness in step (h), the second thickness being defined between the backing film and the second mask and being greater than the first thickness, and in step (i) inducing partial curing of a plurality of protrusions, and in step (j) removing the second mask; m) immersing the foraminous element and partially cured resin thereon in an oxygen-free environment; n) exposing the foraminous element and partially cured resin thereon to light having an activating wavelength to fully cure the partially cured resin.