Here’s something that you don’t hear about, “Rapid Dry Plate Processes”. It seems oxymoronic to put the words “rapid” and “dry plate” together in one sentence. Our friend, Thomas Sutton not only does that in his book, “The Collodion Processes, Wet & Dry” 1862, but he also raves about the quality and that they have the same exposure times as the Wet Collodion process. I did a show on it last August, you can see it here if you’re interested.
So what’s the takeaway? It’s very simple, he substituted the tannin in the process with gum arabic. And he has equal parts of iodide and bromide in the collodion. What does that do? It increases the sensitivity of the plate, or the ISO/ASA to equal that of the Wet Collodion process. So, guess what? You get the convenience of the dry plate process (not packing a darkroom and chemistry around) with the exposure speed of the wet plate process. It’s funny to talk about how “fast” wet collodion is! In comparison to the dry plate process, it really is.
STEP 1: CLEAN AND ALBUMENIZE THE PLATE
I recommend cleaning and albumenizing the plate first. Sutton recommends an India rubber and keroselen mixture that has gone the way of the Dodo bird. Use albumen - one large egg white to 1 L DH2O and a drop or two of ammonia. Clean the glass, steam the plate (humidifier) and flow the albumen on. Let them dry in a clean environment.
STEP 2: FLOW THE BROMO-IODIZED COLLODION
Sutton is adamant that you use a collodion that has both an IODIDE and a BROMIDE in it. There are reasons for this and you can read about them in his book. He says that 5 grains per ounce of a mixture of iodide and cadmium bromide to the ounce (equal parts). That means 500 ml would have about 5 grams of salts; 2.5 grams of each.
STEP 3: SENSITIZE THE PLATE IN A 30-GRAIN BATH
The bath should be a 30 grain bath (65 grams of AgNO3 to 1 liter of DH2O) and slightly acidic (pH 4 - 5) or neural. Sensitize as you normally would - 2 to 5 minutes. If you have to acidify, use glacial acetic acid, not nitric acid.
GO RED LIGHT AT THIS POINT
STEP 4: WASH THE PLATE IN DH2O
It’s important that you wash ALL of the free silver from the plate. Use two trays with DH2O in them. Wash the plate for a minute in the first tray (with agitation) and then a minute or two in the second tray with agitation.
STEP 5: FLOW THE GUM ARABIC…. BUT WAIT….
Here’s where we run into a bit of fun. Sutton calls for 25 grains per ounce of gum arabic. That means you would add 54 grams (5.4%) of powdered gum arabic to 1 liter of DH2O. If you buy liquid gum arabic (and most do) you need to do the math on 14 Baume liquid Gum Arabic. That means you would calculate the 14 Baume to 9.5% - cut that in half and you have Sutton’s weight. So, dilute your liquid Gum Arabic by 50% - 100 ml DH2O to 50 ml Gum Arabic. You can calculate by specific gravity, too - that number would be SG 1.106 - Does that make sense?
STEP 6: LET THE PLATE(S) DRY
Store away the plate(s) in a dry, dust free area and allow them to dry.
STEP 7: EXPOSURE
This is where things change in the dry plate world. Sutton claims that the exposure times for the Rapid Dry Plate is that of the Wet Plate process. It’s that simple.
STEP 8: DEVELOPMENT
I’m going to go into a little more detail here. There is a “pre soak” for Tannin plates with Gallic Acid you can use to make “softer” negatives (not so harsh and dense). This is not needed, but you can read about in the Tannin section of the book.
Start by wetting the plate with DH2O. Mix (fresh) 1 gram of pyrogallic acid into 250 ml DH2O. Add 22 ml of acetic acid. Have some AgNO3 ready to add to each cup of developer. Use a 20 grain solution - 4.4% - have a 100 ml of this mixed and ready to use in the pyro. That’s 4.4 grams into 100 ml DH2O.
After wetting the plate, pour the pyro over the plate with a few drops of the AgNO3 added to it. The image will appear quite rapidly. Develop until you have the correct density.
STEP 9: WASH AND FIX
After development, wash the plate well (you can use tap water). Then fix in a bath of sodium thiosulfate. Mix your fix at 15% - 150 grams of sodium thiosulfate to 1 L of DH2O. And then wash for 20 minutes in running water.
STEP 10: VARNISH
Sutton recommends using a “French Varnish” - which is shellac. You can use either shellac or gum sandarac. The surface of these are pretty tough but he still recommends varnishing.
Shellac Varnish (12%):
60 grams of Dewaxed Super Blonde Shellac Flakes
490 ml Grain Alcohol
10 ml Lavender Oil.