The Photo Relief technique, developed at the turn of the 20th C, is one of the few methods of ceramic decoration able to reproduce a permanent fully continuous tone image on a ceramic surface by combining the use of varying glaze depths with a relief image on the ceramic surface.David Huson and colleagues at The Centre for Fine Print Research have conducted a research project to re-examine the original photo ceramic relief imaging techniques, to assess how modern technology and materials may facilitate both its improvement and application for contemporary use in tiles, architectural panels and other ceramic artifacts.One of the principal strands of investigation has focused on the use of digital technology for the creation and conversion of images into relief surfaces to establish alternatives to the traditional photomechanical relief forming processes.By the use of digital image processing techniques, 3D design software and a desktop CNC milling machine, it has proved possible to develop a process that enables a 3D relief image to be machined into a ceramic mold, or directly into a ceramic substrate. The application of a specially tinted glaze to the relief produces a permanent continuous tone photographic image.
David Huson, Stephen Hoskins, Paul Thirkell, "Photo Ceramic Relief Imaging" in Proc. IS&T Digital Fabrication Conf., 2005, pp 39 - 42, https://doi.org/10.2352/ISSN.2169-4451.2005.21.2.art00015_3