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Electroplating for alternative, non-silver photography

2004

Hello all, first off, please forgive me for my ignorance on the topic. I am just starting my research, so this is the first place I am looking.

I am a photography student at a highly regarded, small college in northwestern Wyoming.

Currently I am interested in non-silver photography. I have recently come across an interesting theory...

There is a process called "gum bichromate" where a pigmented layer of gum arabic is sensitized with a hardening agent (i think silver nitrate is used) the uv-exposed areas then harden the gum and the impregnated pigment is left on the paper when the unexposed regions are washed away.

Here is where my question is. If you take this same principle only use electroplating, an image could be made of extreme archivability, meaning, it could last longer than any other photograph.

This is what I have in mind, a gum arabic layer would somehow be adhered to a sheet of metal which can oxidize to a very dark color, such as bronze. The gelatine, left unpigmented would be exposed as you would a bichromate print, only with a positive not a negative. Then washed off jut as you would a bichromate print leaving the hardened exposed gum.

The metal support would then be electroplated with a white metal, such as zinc, platinum or silver. Because you cannot (as far as I know) plate silver with silver or platinum or plate gum arabic (that much I do know!) the unexposed portions would become plated while the exposed portions unplated. The gum arabic would be washed away using turpentine [on eBay or Amazon] or similar, and the unplated region would be oxidized to it's maximum using whatever process needed (chemical, heat, or just letting it sit around for a few months), resulting in a positive image.

The benefit is because there is no sensitized material in the print, and because oxidization will only get darker, not lighter, the print cannot fade due to atmospheric or photographic conditions. As long as the plating is not compromised physically, the print could in theory last much longer than traditional gelatine prints.

Of course the whitepoint will be reflective, however, I do not see this as much of a problem given that it is an alternative process to start with and not intended as general photography. The process is is non-silver because the image making devices are not sensitized and that any white metal will do.

Please let me know where I can find information on electroplating. If you have a simple recipe and where I can find the ingredients, as well as wattage and time requirements, let me know.

As a photographer I am very aware of the dangers of chemistry and how and where to get MSDS information, however, vapors are my biggest concern given my facilities to carry out this experiment.

Shawn Kearney
artist - Casper, WY, USA

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You have the seeds of an interesting if not complicated process. Firstly, you are partially describing a concept similar to one called electroforming, where you create a pattern on a metal sheet using an insulating material. This can be done with resins such as gum arabic that is can be polymerised by exposure to light. This can be done by adding hexavalent chromium to the resin. If the exposure is through a pattern, only parts of the resin will be polymerised and the other parts can be washed off to leave the bare metal exposed. Metal can the be electrodeposited onto the exposed metal areas. You also have a few misconceptions - you can plate silver with silver, or indeed most electrodepositable metals. Secondly you can metallise resins, using a technique known as "plating on plastics", but the problem will be that the resin film will be so thin it is almost impossible to handle without it being on a strong substrate. I suspect you are thinking that you cannot electrodeposit metal onto conventional photographic film, which to a certain extent (but not totally) is true. The reason for this is that in modern film, the silver is finely distributed throughout a soft resinous layer and this layer is electrically insulating. You also mention non silver photography - how about Degeurretype - he used copper and mercury(!). You should be able to use any metal that has a soluble salt that is reduced to the metal state by light. Furthermore, you will run into one big problem, that of contrast; your idea is based on getting contrast by altering the colour of the resin. This is only practical within a narrow range of intensities. You may be better off thinking in printing terms and use microscopic dots to create contrast. Finally, I would suggest you seek out books on electroforming and "mandrel (or template) making" technologies. You will also get some help from books or technical articles on photolithography and photopolymerisation. I think you have some good ideas that need further work and a lot of practical experimentation, so get into a controlled-light room and start exposing!

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004

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2003

On the general subject of non-silver photography...

It may not offer what you seek, but it is possible to put a projectable 'photograph' on a clear sheet of mylar with no ink, dye, or chemical of any sort--just an embossed diffraction grating. Just before the age of digital everything, I worked with a company that was replacing microfilm by putting 6000 pages of text or drawings on a 12 inch dia. sheet by simply stamping mylar with highly accurate electroformed stampers. It only worked for black and white.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey