In the mid-1800s, Sir John Frederick William Herschel discovered the (ultraviolet) light sensitive properties of certain organic iron compounds found naturally within the plant kingdom – coining the name Siderotype for these general processes, salts of iron mixed with vegetable acids. UV light transforms the light sensitive iron portion of the chemistry into a form of iron that can then react with a metal salt to produce the final image in that salt’s metallic state. With the help of his friends Dr. Alfred Smee, Anna Atkins, William Henry Fox Talbot, and Louis Jacques Mande Daguerre throughout the 1800s, they together solidified the bedrock of photography as we know it today.

Time marched along and then came high resolution digital cameras and affordable archival/gallery/museum quality color printers when a funny thing happened. With the commoditization of high resolution digital cameras and archival quality, digital printmaking systems, along came the ability to produce high resolution digital negatives for analog contact printing processes. In one fell swoop the advent of high quality digital cameras & printers decimated the end game of wet print creation while at the same time enabling a resurgence of historic wet photographic processes that can only be performed via contact printing. What is old is new again, in a very big way.

Preparing the Digital Image
Jamie Taylor has put together a guide to help in preparing a digital image negative for contact printing with these photographic processes, available here in PDF Format: Preparing Digital Negative