Welcome to Mark Eshbaugh's Mordancage reseach page. Mordancage is a process in which a silver gelatin print (rc or fiber) is placed in a solution that makes the gelatin surface of the print pliable and easy to manipulate in the portions of the print that is maximum black. It was first mentioned in a book by L.P.Clerc, but the verison used today was developed by Jean Pierre Sudre around 1972. It was a word of mouth process until recently. After Sudre's passing his friend Craig Stevens translated his notes and that is the formula we use today. I am a former student of Craig and continue to teach the process to my university students.
The formula for the solution is as follows:

The chemistry used in this process is dangerous follow all safety guidelines!

Water - 750 ml
Copper Chloride - 10 grams
Glacial Acetic Acid - 50 ml
30% Hydrogen Peroxide - 25 ml
Water to 1 Liter

Examples of this process utilizing my research are below:

© Bryant Richards
© Bryant Richards
© Bryant Richards


Some papers work better than others for this process. Each paper used here has a good lift of the gelatin. Once the image has been bleached out in the mordacage solution and thoroughly rinsed (the hotter the rinse water the more gelatin release you will get) you can redevelop it in a variety of different developing agents. I've broken down the colors percieved during redevelopment by the most common developing agents. Curiously during redevelopment exposure to ultraviolet light will rapidly increase the time it takes for the image to develop back. In my experiments, I mixed the developer each with the following formula to make my stock solution:

Developing Agent- 3 grams
Potassium Bromide- 5 grams
Sodium Carbonate- 15 grams
Sodium Sulfite- 15 grams
water to 1 liter

For each developer I work with five different dilutions. The colors percieved in redevlopment can be seen on the following pages.

(this is a really non-standard formula for amidol but i wanted consistency in the formula)


(note: results with Phenidone were so comprable to Glycin I didnt bother to scan them)


P-Aminophenol Hydrochloride


Though I have reached a great deal of control in my own work. In general, the process is difficult to control. These are merely guidelines for your color during redevelopment. I have done tests with Phenidone they are rather similar to Glycin and therefore didnt feel like taking the time to scan them. Bear in mind that you can combine the developing agents in any given developer, and they may be used fresh or oxidized as well.

Thank you to my Lab Assistants -Celine and Martha for their help during this research.

Thanks to the Byrant Richards Gallery for hosting this page

Links for more examples of the process

If you have any questions on the process feel free to Email me

© 2005 - Mark L. Eshbaugh