Newly discovered principles of sensitized and super-sensitized photoacid generation from iodonium salts in polymeric films coupled with advances in acid amplification are combined with indicator dye technology and fixing mechanisms to provide a silverless photographic process. This new, single-sheet, negative-working medium is imaged with light and developed and fixed by heating, with no washing, waste, or additional chemicals. In trichrome films with good pre-exposure shelf-life, optical exposure to Dmax requires on the order of 10 mJ/cm2 in the red, 5 mJ/cm2 in the green, 1 mJ/cm2 in the blue, and 0.5 mJ/cm2 in the near- UV. This is too slow for image capture, but already sufficient for many analog and digital printing applications. The intrinsic resolution of the medium permits full-color pixels less than 10 microns in diameter, with continuously variable levels of gray for each pixel.
John L. Marshall, Stephen J. Telfer, "Photography via Photoacid Generation and Amplification" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP18), 2002, pp 445 - 449, https://doi.org/10.2352/ISSN.2169-4451.2002.18.1.art00006_2