How do you prepare a glass plate for use as a neg

waynecrider · Jul 20, 2005

Total newbie here, and having not read too much on the subject, I was wondering just how glass plates are coated, or sensitized, for use in todays world. Can someone clue me in on the procedure and how adhering the emulsions are.

JG Motamedi · Jul 20, 2005

Wayne,

I think the only commercially available glass plates are from Russia made by Slavich.

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If you are wondering about a do it yourself version, you have a few choices, suspending silver salts in collodion, albumen, or gelatin.

Lots of details here:

http://albumen.stanford.edu/library/monographs/sunbeam/toc.html

Collodion, especially wet-plate collodion is having a great comeback in recent years, and you could probably find a weekend seminar near you to learn. Its not terribly difficult, but does take quite a bit of effort. Here is a brief summary from Wayne Pierce:

http://www.companyphotographer.com/html/instructions.html

Once you get collodion wet-plate under your belt, you can try collodion dry-plate. Same basic idea, but with a bit less speed and a few more steps.

I know there must be people out there making gelatin dry-plates, but I don't know any personally. Some details here:

(there was a url link here which no longer exists)

Considering the much touted "death of film" (tongue firmly but cautiously in cheek), it would make sense for somebody to start working on a reliable gelatin dry-plate, any comments?

TheFlyingCamera · Jul 21, 2005

There is an excellent book out there that covers in some but not excruciating detail a wide range of "alternative" processes - Coming In To Focus, by John Barnier. He gives a good overview of wet-plate collodion.

Just a word of caution - the chemistry involved in wet-plate collodion is pretty nasty. Collodion (nitrocellulose... aka the movie film that goes BOOM!), ether (to dissolve the nitrocellulose so it will flow and adhere to the glass plate), hydrochloric acid, and cyanide. It can of course be done safely, but requires a modicum more advanced preparation and consistency of method.

The best thing to do as far as prepping glass plates is to order the glass pre-cut, and then polish the edges to smooth them so you won't be adding blood to the emulsion. The Barnier book gives an excellent summation. Having watched someone actually do wet-plate work, it is fascinating, and it is a relatively quick process (it has to be, because the plate has to be wet while being exposed).

removed account4 · Jul 21, 2005

hi wayne

i've coated dry plates using store bought emulsion ( read: liquid light ) off-and-on since about 1986-7. there are other brands out there, some are variable contrast, and some are faster.

the main thing you have to worry about is creating a binding agent to for subbing your plates. i've tried a bunch of different ones from albumen to colodion ( bought at the pharmacy ) in addition to gelatin and urethane.
while the urethane works well, it yellows over time. the best i have used is knox gelatin. i know it isn't photo grade like the formulary or b&s sells, but it seems to have worked.

you need to clean off the glass before subbing -
wash well with a brush and washing soda and flow stop bath or vinegar over it so it "sheets off". you let the plates dry and you can either "flow"
the gelatin or brush it on. a few coats with drying inbetween.
some folks add alum hardener into the gelatin, i hear it works well, but have never done that myself ...

there are a few different ways to coat the plates. i have used those cheep foam brushes, and i have just poured the emulsion over the plate. you can put a few coats of the emulsion on as well. i haven't coated in a while, but when i did, i would have a hair dryer to dry the emulsion faster than "air drying". some say aged emulsion offers more contrast, other say you can increase speed by adding a little developer ( like dektol or whatever you use ) to the emulsion. the asa of liquid light is somewhere between asa 1 and 5, depending on the light conditions, age of the emulsion and wheter or not you incorporated developer. after you make your exposure you process like paper under a red light. a few things to worry about: if your binder didn't hold down your emulsion completely, it will lift off the plate, stretch and crease, or it will lift off, and you will lose your image down the drain - kind of like a polaroid emulsion transfer

there is a bunch information here ( probably explained better than i did ): http://www.alternativephotography.com/process_dryplate.html

and the book "liquid silver emulsion" is pretty much the bible on this sort of thing: http://www.alternativephotography.com/books/sm_r_silver_gelatin.html

good luck!
john

JG Motamedi · Jul 21, 2005

John,

Thanks for the interesting post. Have you tried to make your own gelatin emulsion with that Kodak recipe or know of anyone who makes their own? I have been itching to try dryplate for a while now. Wet-plate is great but I can't move more than a few meters from the darkroom. How many plates can you get out of a bottle of light?

jason

ps: I think the "dangers" of collodion are overstated. Cutting glass is very easy as long as you spend the $20 on a good oil-type cutter (Toyo makes a great one). Also, the set-up isn't likely to blow up, since collodion is only dangerous at one stage of its production, and very few people make their own collodion; it is commercially available. Lastly, there is no reason to use potassium cyanide as a fixer, regular hypo works just fine.

shinn · Jul 21, 2005

"silver Gelatin" written by martin reed and sarah jones goes into great detail about making silver gelatin emulsions with a lengthy section on glass, and a good section on troubleshooting...which is needed....cause I didn't find this easy to do.

The book of alt processes by christopher james also gets into working on glass as well.

Making it from scratch is a bit of a PITA...for me the most difficult part was temperature control which decides speed and contrast, but I now have a hot plate/stirrer which should make things a lot easier next time. I hope.

Happy Days
Mark

Claire Senft · Jul 21, 2005

The product may have been discontinued but Kodak was making Tmax 100 glass plates and I think Technical Pan also.

JG Motamedi · Jul 21, 2005

Claire Senft said:
The product may have been discontinued but Kodak was making Tmax 100 glass plates and I think Technical Pan also.

All Kodak glass plates were discontinued about four years ago. I think they were used primarily for astronomy and electron microscopy, and were incredibly expensive.

I do recall seeing some Agfa glass plates for sale somewhere.

David A. Goldfarb · Jul 21, 2005

The Slavich plates can readily be found at holography suppliers. There's a panchromatic emulsion, an ortho emulsion, and some specialized emulsions more for holography and scientific use.

Ole · Jul 21, 2005

JG Motamedi said:
All Kodak glass plates were discontinued about four years ago. I think they were used primarily for astronomy and electron microscopy, and were incredibly expensive.

That should be about right, I just got two boxes of 13x18cm plates off German ebay. But they weren't that expensive - now. About 2 Euro apiece - 50 Euros for two boxes of 12.

smieglitz · Jul 21, 2005

JG Motamedi said:
All Kodak glass plates were discontinued about four years ago. I think they were used primarily for astronomy and electron microscopy, and were incredibly expensive...

Well! That news really rocks my world. I figured the TMX (and other) technical plates would be one of the last Kodak products to disappear. I can see them killing off all their Art products but I thought the Science products would continue to be manufactered even if the demand was miniscule.

So much for dimensional stability. This is gonna put me over the edge.

Joe

removed account4 · Jul 21, 2005

hi jason

i have been itchin' to use the kodak recipe, it looks easy enough ... but haven't had a chance to, so i broke down and bought another quart of liquid light. it is kind of the same but better ....

Ryuji Suzuki ( http://www.silvergrain.org ) has a ton of experience making his own emulsion. he used to post here from time to time ... maybe he'll chime in ?

-john

waynecrider · Jul 21, 2005

So there's a few ways to go and lots of reading to do. Can anyone tho give me any idea as to archival qualitites in any form. Also, why doesn't any coating just come of the plates?

JG Motamedi · Jul 21, 2005

Can anyone tho give me any idea as to archival qualitites in any form

Collodion negatives on glass are, if properly processed, as archival as any other B&W process. That is to say, they meet or exceed most archival standards.

why doesn't any coating just come of the plates?

Sometimes in processing collodion does come off the plates. In general however collodion, albumen, and gelatin manage to adhere. The glass must be very well cleaned; I use a combination of rotten-stone and alcohol to really scrub (but not scratch) the plate before pouring the emulsion. Perhaps the emulsion adheres to the roughened edges of the glass more than the smooth center.

Sometimes, with particular kinds of salts and glass the collodion will not stick, and it has to be "subbed" (from substratum) before applying the emulsion. Meaning; a thin layer of dilute albumen is flowed and dried on the plate before the collodion. After this is done, the collodion will stick like glue.

Hope this helps.

Donald Qualls · Jul 21, 2005

Okay, from back up the thread a little -- collodion is flammable and may be subject to long term deterioration a la nitrate movie film, regardless of the stage of production. I speak from experience, having once accidentally ignited a model airplane coated with nitrate dope (collodion in all but name) and watched all the tissue paper covering burn off a wing in about three seconds. And the nitocellulose used as a propellant in all modern ammunition differs from collodion only in the level of nitration -- collodion is the middle grade (celluloid is least, guncotton or nitrocellulose is the most).

Not to mention that ether is flammable enough it's used as an aid to starting engines when they're too cold to start on gasoline or diesel, and is capable of oxidizing to a friction sensitive explosive in storage (and never mind its anesthetic/intoxicating effects).

Wet plate isn't impossible, surely, but there are very good reasons most of the photographic world abandoned it as soon as dry plates became commercially available.

JG Motamedi · Jul 21, 2005

If "collodion is flammable and may be subject to long term deterioration" I would like to know why there are many thousands of tintypes and ambrotypes in existence in beautiful shape? Once dried collodion is no more flammable than a plastic bag. Do you worry about all those plastic bags in your house? It is NOT like nitrate film.

But seriously, yes, liquid collodion contains both ether and alcohol, both of which are flammable (like gasoline) and inhaled or imbibed in sufficient quantities will stupefy, and eventually kill you (like gin). But don't listen to me, read the MSDS

http://www.jtbaker.com/msds/englishhtml/c5060.htm

Silver Nitrate--another major ingredient--will if splashed in your eyes blind you, and will dye your skin dark brown. So beware and keep buying off the shelves!

Donald Qualls · Jul 22, 2005

Collodion *is* like nitrate film -- celluloid and collodion are nearly identical, chemically. Film is more prone to deterioration because, when it was being made by the thousands of miles, some of it was not propertly neutralized, and the residual acidity causes the breakdown that can cause spontaneous combustion. This has been less of a problem with collodion plates because, first, the collodion coating process tends to neutralize any residual nitric acid, and second, because these are seldom if ever stored in airtight cans with many pounds of the collodion sealed in, so they don't accumulate the deteriorate products that accelerate the breakdown (as happens with nitrate film).

However, in the late 19th century, collodion billiard balls were well known to make a gunshot-like crack when they struck from a hard shot, and occasionally to burst into flame from this; collodion collars were also known to catch fire and burn with great rapidity, severely injuring a number of men who were wearing them when this happened.

Try this as an experiment: take collodion and dry it on a substrate to which it doesn't adhere, then peel off the resulting sheet. Hold it with tongs and touch a match to it -- I think you'll then agree with me that collodion is vigorously flammable. You won't find the same thing with plastic bags, which are made of polyethylene (mostly).

JG Motamedi · Jul 22, 2005

Donald Qualls said:
Try this as an experiment: take collodion and dry it on a substrate to which it doesn't adhere, then peel off the resulting sheet. Hold it with tongs and touch a match to it -- I think you'll then agree with me that collodion is vigorously flammable.

I stand corrected. Sure enough, my little dried piece of collodion went poof! quick up in flames, kinda pretty like flash powder.

I tried the same with a tintype, but it didn't ignite at all, it just smelled like lavender from the varnish. This does bring up an issue; when drying collodion plates they are exposed to direct flame and heat. I have personally dried a hundred+ plates, and I know folks have have done several thousand, and I have never heard anybody complain that their collodion ignited on the plate.

So Donald, why don't my tintypes ignite?

removed account4 · Jul 22, 2005

waynecrider said:
So there's a few ways to go and lots of reading to do. Can anyone tho give me any idea as to archival qualitites in any form. Also, why doesn't any coating just come of the plates?

wayne - not sure why, but sometimes the emulsion won't stick to some of the subbing agents, even though these subbing agents will stick to the glass. i've a photographic annual from 1904 with recipes for albumen and collodion "stuff", and while i was able to get both substances to adhere to the glass plate ( well cleaned ) the liquid light just didn't stick to the subbing agent and didn't dry out ... i didn't use the blow dryer, knowing the flame-issues with collodion, and it didn't help much with albumen. i don't have experience with other methods or processes, like wet collodion, or tin types, ambrotypes &C which are very similar, but from my understanding the silver nitrate is suspended in the collodion, rather than suspended in gelatine ... ( like (dry plate) liquid silver emulsion ) ...

after i realized that it was a waste of my time to use it as a "subber", i did play around i with my pharmacy bought collodion. i made small molds and poured it into them. when the collodion dried out, i carefully pulled them out, inked and etched them and used them in my enlarger like film. ink and dyes go right *into* the collodion and are not on the surface, so, when they were enlarged, the drawn images had a nice 3-D effect. when i was done, i found a nice open place where i ignited my little art project.

jason -
maybe your tintypes don't ignite because the collodion has bonded a different way with the asphalt-like substance that also coats the tin? judging from the way inks wander into the collodion, i wouldn't be surprised that something similar might be happening with the asphalt, and it is dispersing( if that makes sense ) the flammable quality.

TheFlyingCamera · Jul 22, 2005

JG Motamedi said:
I stand corrected. Sure enough, my little dried piece of collodion went poof! quick up in flames, kinda pretty like flash powder.

I tried the same with a tintype, but it didn't ignite at all, it just smelled like lavender from the varnish. This does bring up an issue; when drying collodion plates they are exposed to direct flame and heat. I have personally dried a hundred+ plates, and I know folks have have done several thousand, and I have never heard anybody complain that their collodion ignited on the plate.

So Donald, why don't my tintypes ignite?

they probably don't ignite because of the varnish.

I do know someone who has had glass plates burst into flame and shatter in his hands while coating... it happened when he was trying to keep a plate warm enough for the collodion to stay fluid while photographing in the field in Montana in the fall. He was coating it over a gas jet.

JG Motamedi · Jul 22, 2005

TheFlyingCamera said:
I do know someone who has had glass plates burst into flame and shatter in his hands while coating... it happened when he was trying to keep a plate warm enough for the collodion to stay fluid while photographing in the field in Montana in the fall. He was coating it over a gas jet.

This is a new one to me. Coating over a flame. Hmmm, not very smart. There would be better ways of keeping the collodion warm, like keeping the bottle in warm water. Anyhow, there are different recipes for summer and winter collodions; changing the ratio between ether and alcohol.

But I have dragged the thread from from its origin. Sorry Wayne!

Peter Rockstroh · Jul 22, 2005

I have never prepared collodion, but I used to make nitrocellulose lacquer - which apparently is the same thing - by the ton. The solvents used for it are all highly flammable, yet I never used ether (too flammable, explosive and expensive). Is there any advantage of ether over the usual solvents for NC ? (ethyl acetate, butyl acetate and cellosolve). My only variations of the lacquer formulations were usually related to balancing solvents for a drying rate that would avoid whitening of the coating (due to water condensation in the film while drying).

Donald Qualls · Jul 22, 2005

Different solvents are required for different nitration levels on the nitrocellulose spectrum. This was the original distinction between guncotton, collodion, and celluloid. The more nitration, the "hotter" solvent is needed. The ether-alcohol mix used for collodion will work with NC lacquer (which is collodion/celluloid), but there's enough celluloid in the mix that toluene, xylene, and the acetates you mention will work, with greater safety. Straight collodion won't dissolve in toluene (the strongest solvent normally used in NC lacquer), only in ether/alcohol (or nitroglycerine, but that's not really an improvement in safety, is it?).

Why won't your tintypes ignite? Most likely because the plate conducts off enough heat to keep the collodion from reaching a self-sustaining reaction rate before you give up. Possibly also because the bitumen or asphaltum (or modern equivalent) used to japan the plate acts as what explosives chemists call a "phlegmatizer" and reduces the sensitivity and/or reaction rate of the collodion. Or just possibly the lacquer admixes with the collodion in some fashion that makes it act more like modern thermoplastics than collodion; if the lacquer is strongly endothermal it might prevent the reaction becoming self-sustaining.

Gerald Koch · Jul 22, 2005

Theoretically you can prepare cellulose mononitrate, cellulose dinitrate, and cellulose trinitrate. Practically when you react cellulose with nitric acid you get a mixture of at least two of the nitrates. The actual composition depending on the nitrating mixture and the length of time for the reaction. Collodion is primarily cellulose dinitrate. It is still sold to cover wounds.

Glass for photographic plates may be slightly etched on one side with hydrofluoric acid. The etching is slight but provides a better tooth for the emulsion to bind to it. The plate may then be coated with egg white and dried before the collodion or gelatin emulsion is applied.

Using hydrofluoric acid requires rubber gloves as it can cause serious burns which are slow to heal.

waynecrider · Jul 22, 2005

Gerald Koch said:
Glass for photographic plates may be slightly etched on one side with hydrofluoric acid. The etching is slight but provides a better tooth for the emulsion to bind to it. The plate may then be coated with egg white and dried before the collodion or gelatin emulsion is applied.

Ok, asking as a novice, will the gelatin stick to the plate by itself without using egg white (do you just use plain ol egg's?) and is there any tint to the gelatin. If using egg white does it impart a color? I'm leaning towards buying some photographic gelatin and trying it.

On the topic of hydroflouric acid, I know it's sold thru various art and crafts stores. Does the roughened glass surface cause problems when printing?

How do you prepare a glass plate for use as a neg

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