What Kind of Paint or Varnish Was Historically Used on Ambrotypes?

[D_Quinn]

I recently got this 19th-century ambrotype at an antique market in Japan. Since I do wet plate photography myself, I’m curious about the type of paint or varnish that was historically used back then.

Since this is an ambrotype, the collodion side needs to be backed with a black cloth or some kind of black paint (or varnish) to make the image appear positive. As you can see in the picture, it’s not black paint but more of a dark amber color. It’s also somewhat transparent.

I don’t think the paint used was unique to Japan, as the technique was originally brought from abroad. I’m wondering if I could apply this type of paint to my own ambrotypes.

If anyone has expertise in historical wet plate photography, I would love to learn more!

Thanks in advance!

 

[BrianShaw]

Ambrotype photography — Photocritic Photo School

The ambrotype process is a photographic process that creates a positive photographic image on a sheet of glass using the wet plate collodion process. It was invented by Frederick Scott Archer in the early 1850s, then patented in 1854 by James Ambrose Cutting of Boston, in the United States. This t

www.photocritic.org

 

[koraks]

As you can see in the picture, it’s not black paint but more of a dark amber color. It’s also somewhat transparent.

I'm going to take a guess here: I think they just held the plate over a flame so soot deposited onto the back. The color is reminiscent of finely divided carbon nanoparticles and the way it scratches also reminds me of a thin layer of soot. You could apply a layer of e.g. shellac over the soot to make it a little more robust.

 

[D_Quinn]

Thanks for your responses!

I do think gum sandarac varnish was used, but since the varnish alone is quite transparent despite its slight yellow tint, I don’t think it would create this kind of appearance. (I also apply gum sandarac varnish to my plates, and this looks different from my varnished plates)

It certainly does resemble soot. I’ve seen many ambrotypes in Japan from the same era with this type of sealing or backing. I’m going to look into whether something like this was done in the conservation of antique ambrotypes.

 

[BrianShaw]

Everything I've ever seen about ambrotypes has refered to "black varnish or paint", or black paper backing. Not very detailed. In my modest collection, I don't believe any of them have black paper, though. Varnish alone without a blackening agent/pigment certainly wouldn't work. Carbon/soot seems like it might be plausible but I'm not too sure about using a heat source to depsoit the material. Seems potentially injurious to the emulstion.

Looking at a couple of photographic conservation books I have, the "universal" reccomendation for conserving ambrotypes is a ph-neutral black paper. They specifically cite concern of damage to the emulsion.

Reilly, James. Care and Identification of 19th Century Photogrpahic Prints. Kodak publication G-2S. 1986
Ritzenthaler, Munoff, and Long. Administration of Photographic Collections. The Society of American Archivists. 1985.

 

[BrianShaw]

I had an idea...perhaps spmething like thios might yield insight. I have not read it yet but won't get to it soon so post for you to investigate.

The photograph and ambrotype manual : a practical treatise on the art of taking positive and negative photographs on paper and glass, commonly known as photography, in all its branches ; containing all the various recipes practiced by the most succes

First published in 1856 as The ambrotype manual

archive.org

The photograph and ambrotype manual : a practical treatise on the art of taking positive and negative photographs on paper and glass ... : Burgess, N. G. (Nathan G.) : Free Download, Borrow, and Streaming : Internet Archive

First published in 1856 under title: The ambrotype manual

archive.org

Photography in a nut shell; or, The experience of an artist in photography, on paper, glass and silver, : with illustrations. : Simons, M. P. (Montgomery P.) : Free Download, Borrow, and Streaming : Internet Archive

Copyright 1858 by M.P. Simons

archive.org

 

[retina_restoration]

Asphaltum made into a “paint” with a solvent (like mineral spirits” was often used to black the backside of Ambrotypes. It’s still used today and is described in most of the modern manuals (Coffer, Jacobson, et al)

 

[koraks]

Carbon/soot seems like it might be plausible but I'm not too sure about using a heat source to depsoit the material. Seems potentially injurious to the emulstion.

The plate doesn't have to heat up appreciably. Just run it across the top of a flickering flame. It won't get very warm, but a layer of soot will deposit on it.
A carbon pigment can be suspended in a varnish, but you'd effectively be making a very crude paint. So in that case, I'd just use a paint and call it good. Don't underestimate the challenge of dispersing carbon in a liquid. It's not necessarily very easy to get it right.

 

[BrianShaw]

Asphaltum made into a “paint” with a solvent (like mineral spirits” was often used to black the backside of Ambrotypes. It’s still used today and is described in most of the modern manuals (Coffer, Jacobson, et al)

Ah, yes… asphaltum.

Google Search

 

[D_Quinn]

Thanks, everyone! It just looks like thinned-out asphaltum. Finding a small quantity of asphaltum seems difficult, but I’d like to try it out in the future. It has a different quality compared to using black velvet behind the glass plate. My only concern is how achievable it is, but I don’t really worry about what happens after I die, haha.

 

[koraks]

My only concern is how achievable it is

You mean archival stability? I wouldn't worry about it; it's basically carbon. Very stable.

You could achieve a very similar effect if you just dilute black India/Sumi ink in a suitable carrier and apply that to the plate.
Personally I often used either spray paint or acrylic paint. Both worked fine.

 

[D_Quinn]

You mean archival stability? I wouldn't worry about it; it's basically carbon. Very stable.

That makes sense. Thanks!

You could achieve a very similar effect if you just dilute black India/Sumi ink in a suitable carrier and apply that to the plate.
Personally I often used either spray paint or acrylic paint. Both worked fine.

Spray paint indeed seems so much easier.

 

[BrianShaw]

To answer the historical question (something I always found interesting yet never researched), there are several 1864 formulas for ambrotype backing varnish in John Towler's various books. See page 74 of this one, for example

The American photographic almanac 1864.

 

[retina_restoration]

Thanks, everyone! It just looks like thinned-out asphaltum. Finding a small quantity of asphaltum seems difficult, but I’d like to try it out in the future. It has a different quality compared to using black velvet behind the glass plate. My only concern is how achievable it is, but I don’t really worry about what happens after I die, haha.

If you mean "archival", then asphalt backing is about as archival as any material gets.

 

[BrianShaw]

An artist friend suggested this option, pre-mixed asphaltum paint.

Google Search

 

[Romanko]

Finding a small quantity of asphaltum seems difficult, but I’d like to try it out in the future.

Try art supplies. I was able to find Asphaltum pigments (dry powder) here in Australia.

 

[D_Quinn]

Good idea. Indeed, if it's art supplies, they should be easy to find in Japan as well. I'll read the manuals and other resources first and give it a try. Thank you!

 

[Romanko]

Also, asphaltum lacquer coating is called "japanning". It was used as a cheap imitation of the traditional Japanese lacquer. If you are in Japan you might be able to find some artisans who are still using the original technique. The ingredients are most likely hard to find and very expensive but so is the ambrotype.

The usual advice applies of course of making the best copy of the artifact (digital and/or copy negative/print) before attempting any restorations. Good luck.