The doretype is a photographic printing and finishing process that held the interest of many photographers during the heyday of dry glass plate photography from near the end of the 19th century until it’s general use petered out about 1940. Clayton Harley gives us an overview.
The doretype is a photographic printing and finishing process that was popular during the heyday of dry glass plate photography, from near the end of the 19th century until its use petered out around 1940. The process is also known by the names Orotone, Goldtone and Curt-tone. In short, one makes a positive print onto a glass plate and then backs it with a shiny material such as bronze, copper, gold, or even a fabric like silk. The end result is a positive silver gelatin print upon the shiny (“dore-” meaning gold) background of your choosing, yielding an image that has a brilliant, magical quality similar in spirit to a hologram. The choice of material for backings and their methods of application are many, and so the making of doretypes can be quite varied and artistic.
Step-by-step doretype process:
- Make a positive print onto a glass negative or lantern slide; develop, fix and dry in the usual manner.
- Coat the glass print with gilding size. Gilding size is the transparent adhesive to which you will affix the copper leaf. (Coating the emulsion side of the positive is standard, but coating on the glass side can also be used for a depth effect.) Let it partially dry until it reaches a state of tack (sticky but no longer liquid, approx. 1 hour).
- Adhere the copper leaf to the tacky gilding size. Allow the size to complete drying, preferably overnight.
- Finish the back of the leaf with a protective coating. Anything can be used (gesso, modge podge, resin, really any protective coating) as this will not be seen.
- Frame or display unframed.
The process has seen little attention in the last several decades as it went out of fashion alongside dry glass plate negatives. If you’re not familiar with glass plates, think sheet film but with emulsion on glass rather than film. Wet plate collodion on glass or tin backing (tintypes)is known today as a throwback process, but in the later 19th century it was standard. When working a wet process like collodion, the emulsion needed to still be liquid at the time of exposure, so thin, flimsy film could not readily be used as a backing. Glass or tin made much more sense when working wet processes. As gelatin became standardized in photography, the photo industry moved away from wet to dry emulsions and so it became possible (and more sensible) to use thinner, lighter-weight film as opposed to rigid, heavy glass to back emulsions. However, glass plates continued to be manufactured and widely used for many years because of their ubiquity up until that time. Kodak lantern slide plates were still produced until around 1990, but for all intents and purposes, glass ceased to be standard before WWII.
If you make your own emulsions, coat your own plates, or are lucky enough to have access to premade Kodak, Ilford, or other precoated glass, you can easily make a doretype. The prevailing knowledge in what little literature is available on the subject is that one should make a slightly thinner than normal positive print onto the glass. This allows the shiny backing more interplay with the image than if one prints highlights to full blacks. Personally, I like to have a bit of full black but leave the rest of the negative thinner than I would if I were making a print on paper. That’s my preference, but either way it is true that a bit of thinness in the shadows does yield a nice effect in doretype.
Once you have printed your positive onto the glass, developed and fixed, you can decide on a backing. It is easy to take the positive and lay it out on different types of backings to get a sense of what the finished product will look like. Simply place the glass over the material of your choosing to get the gist. The best doretypes I have made thus far are from bronze leaf. One could obviously use gold leaf (at great cost) or silver leaf (which would, of course, offer a swallowing effect on the silver gelatin emulsion), but you can also purchase bronze, copper, or any other metal in powdered form and mix it into varnish rather than using a leaf (take care when working with powdered metals; powdered selenium is very dangerous, for example).
Any kind of backing, shiny or otherwise, offers different effects and it’s up to the user to apply trial and error to discover which backings will most lend themselves to which subjects. Once you have landed on which type of backing will work best with a certain subject, it’s time to suit printing density to fit that backing. You can also decide whether you want to tone the image before backing it. I believe if you were going to try silver leaf, for example, toning the image to sepia with thiourea would help the image stand out. Tinting can also help, especially if one uses a staining developer.
One added note: I had never used leafing in my art practices in the past. The standard rapid-drying sizing (adhesive) for leafing does dry clear and works well while also preventing the metal of the leaf from coming into direct contact with the silver in the emulsion which could possibly create corrosion over time. Note that the sizing is not good to inhale. I recommend wearing a mask when applying the size to the glass, coating it lightly, and never sniffing the bottle. Also beware that printing on out-of-date glass plates requires considerable darkroom experience and I would recommend trying to make your own fresh glass plates from premade liquid emulsion which can be ordered online. Getting your hands on premade glass plates from Kodak or Ilford on eBay or Etsy may seem like an exciting moment until you drop into the darkroom to find them perilously fogged with age. Only darkroom specialists who mix their own chemistry from scratch should look into the secondhand market to acquire premade plates, as they will be the only workers who can yield acceptable images from such plates.
Thanks to Harvey and Marion Yurow for turning me on to the process and to the following articles:
Two articles published in Kodak Publication STUDIO LIGHT in 1917 & 1922 respectively and archived by the chest of books:
as well as this thoughtful technical analysis of actual antique doretypes by Richard Stenman published in Topics in Photographic Preservation 2011, Volume 14, Article 41 (pp. 263-281) and archived on culturalheritage.org:
and for anyone interested in the history of photographic emulsions and papers, Martin Reed’s indelible and definitive treatise on the subject is the best resource, and he has been kind enough to give me permission to post it to my website. You can read it here: https://www.claytonharley.com/martin-reeds-yesterdays-papers It was originally published in ‘Ag Photographic’ magazine, Vol 10, 1998.
See an example of a Doretype: