While William Henry Fox Talbot is credited with the invention of paper photography, his contribution to the invention of the photogravure is often only a sidebar, despite his spending most of his photographic career working to solve the image permanence problem. Over a span of nearly three decades, Talbot made many hundreds of steel and copper plates and thousands of proof prints. Little is known at present about many of these, but a few carry a hairline trace of an experiment number that was cut into the printing plate with a diamond. The number prints in reverse and being so fine is often almost illegible. In this instance though, we can tease a magnified image out of the paper fibers just enough to make it out. Using that number, we turned to Talbot’s voluminous notes on his experiments. On September 26, 1860 he cited this particular plate:

443. Portrait of girl 3 minutes bright light. Gelatin coating thin – heat but no resin. Etched with 1 and then 2 a long time. Engraving feels rough as if it would print more brilliant than the 2 next, owing to the ­thin gel, & no resin. [1]