A Guide to Platinum Printing
by Joe Lipka
Progress in photography depends on solving a technical problem. No other
art form has that hurdle. One of the first questions photographers ask each other is “How do I…” Well, here the question is, “How do I get started in platinum printing?”
The least expensive alternative is to make wet process copy negatives (assuming, of course, you already have a black and white darkroom). The other two processes can be expensive depending on your level of investment in photography or computers. If you already have a view camera, that major expense is out of the way. Since this article is on the web, you have a computer. Photoshop software is fairly expensive and requires that you learn a new skill. Do not underestimate the effort to become proficient in Photoshop. If you are not amenable to teaching yourself new computer skills this alternative can be time consuming, frustrating and expensive. Computers are the only thing I know that can chew up money faster than large format photographic equipment. If you don’t want to spend lots of money to create enlarged negatives, there are commercial services that can create an enlarged negative for you using either your in-camera negative or a print. For an evaluation, this expense will be cheaper than the above alternatives.
You will need some device to hold the negative in contact with the printing paper. The goal is to keep the negative and paper in direct contact for the duration of the exposure. There are multiple ways of accomplishing this. It can be as simple as taping two sheets of glass with a duct tape hinge or as complicated as a vacuum printing frame. There is no doubt that the “glass sandwich” from your local glazier is the least expensive solution that works as a printing frame. I used one for about ten years printing 5 x 7 and 8 x 10 in-camera negatives. If you use copy film, or lithographic film, then you should use either a spring back contact or vacuum printing frame because of the thin base used in those films. These thin films need the mechanical force of a spring or vacuum to hold the film tightly to the paper. If the film is not held tightly against the paper, the results will be disappointing because the print will either be out of focus or show Newton’s rings. There is no doubt a vacuum printing frame is the best gear for contact printing. If you are a careful shopper the cost of a 17 x 22 used vacuum easel is probably less than the cost of a brand new spring back contact printing frame.
Alternative processes are sensitive to UV light. That’s why an enlarger for alternative processes won’t work.
You can’t see to focus with invisible UV light. Exposure times can also be very long. I have had contact prints
that require 45 or 50 minute exposures. Most of my print exposures are between 6 and 12 minutes. Get out your
calculator to do the inverse square calculation for enlarging time when the light source is a few feet rather than a few inches from the paper. It would be economically (and physically) impractical to build a UV enlarger.
We’ve almost completely set up the darkroom. The only things left are the trays and utensils. No metal is allowed because metal contamination will play havoc with platinum printing. You will need to get new trays, chemical storage jugs and anything else that will touch the paper during processing. It is not necessary to get a new print washer or drying screens, but everything else must be brand new. Thank goodness these last items are not very expensive. That’s a good thing because now we are really going to spend some money.
Making your own Printing Paper
There are a number of excellent detailed descriptions of the platinum printing process available either on-line or in book form. The platinum print is created by UV light converting Ferric oxalate it to its ferrous state. Platinum salts bond to the iron during this process. When developed out, platinum salts are reduced to metallic platinum to create the image. Residual iron is removed in a series of fixing baths leaving an image of metallic platinum embedded in paper. (This embedding of the image in the paper is one of the major differences between alternative processes and silver prints where the image is suspended in a gelatin layer above a substrate.)
The first choice in making a print is selection of the type of paper. Platinum prints can be made on most any type of pure rag papers. A 90-pound cold press watercolor paper would be a good starting point for those that like to experiment. I have tried a few different papers, but I continue to return to Crane’s Platinotype paper. There is something reassuring about using a paper that is manufactured for the purpose.
A warning on the chemicals used in coating platinotypes is in order. These chemicals are poisonous. Instructions on safety and storage provided by the manufacturers are not to be ignored when handling these chemicals. As we all know, there are no “good” non-toxic photographic chemicals. Photographic chemical desirability increases with toxicity, smell and cost. The chemicals used for platinum emulsions max out in two of the three categories (they don’t smell – but I bet you already guessed that).
The emulsion is mixed for each print. I use a combination of four chemicals to create my emulsions. The first two solutions are Ferric Oxalate, and Ferric Oxalate with potassium chlorate. Varying the mixture of these two solutions governs the contrast of the emulsion. The third and fourth solutions, Sodium Chloropalladite and Potassium Chloroplatinite are mixed to control the tone (color) of the photograph. The palladium salts bring a warm tone to relatively cold tone platinum salts. It is possible to use either the palladium or platinum salts by themselves, but generally the two are mixed for both aesthetic and contrast control reasons. You can change the color of the image by toning or applying gum bichromate emulsions to a finished platinum print.
The chemicals are usually stored in brown 60 milliliter glass bottles with eyedropper tops. The eyedropper tops make it easy to mix the correct proportions together. For a typical 8 x 10 platinum print, my “drop count” is 12 – 10 – 8 –16. This means that I use an eyedropper to drop 12 drops of Ferric Oxalate, 10 drops of Ferric Oxalate with potassium chlorate, 8 drops of Potassium Chloroplatinite and 16 drops of Sodium Chloropalladite into a small glass beaker. Some folks use plastic condiment cups liberated from fast food restaurants, or shot glasses. My 50 ml glass beaker looks official, and has a nice little spout to help pour out the emulsion.
To make an 8 x 10 print, I use 11 x 14 paper. This gives a very nice border around the print and leaves room to hold the paper securely during processing without fear of tearing the image while the paper is wet. I outline the image size in pencil using an 8 x 10 cardboard template. Some fastidious printers use masking tape to clearly define their image area, coating only the area inside the tape border.
The emulsion is then poured onto the paper. Traditional platinum printers use a brush to coat their papers. I use a device called a puddle pusher. It is a glass rod that uses the surface tension of the emulsion to evenly coat the paper. I have tried both methods. I think the puddle pusher is easier, neater and possibly more economical than brushing. The paper gets two coats of emulsion and it is allowed to dry both between coats and prior to contact printing.
Processing the Print
After exposure to UV light in a printing frame, the print is ready to be processed. I always use rubber gloves
when processing prints. The traditional formula calls for developing prints in a potassium oxalate solution and
clearing them in dilute hydrochloric acid. This is pretty stern stuff in terms of toxicity and danger in handling.
Modern formulations for the developer use sodium or ammonium citrate solutions. A replacement for the hydrochloric acid, EDTA (ethylenediamine tetraacetic acid sodium salt), can be used as a chelating agent to
remove the iron from the emulsion. The modern developer is not toxic, but becomes toxic as it is used
OK, so how much will this cost?
In short, the answer is, “a bunch”. I estimate my cost to produce a single piece of 8 x 10 printing paper is about $6.50. By comparison a silver print is about $.50. Platinotypes are at least an order of magnitude greater in cost than a silver print. In addition to the cost of producing the single sheet of enlarging paper, there is the expense of producing the enlarged negative. Depending on how you make your enlarged negative the cost can run anywhere from $2 to $200. This is the cost for a “keeper.” You also must consider the cost for test strips and blunders as you learn the process. All these costs add up. The economic pain threshold must be established before starting. This must be considered because, once you produce a good platinum print, you will be addicted to the process.
This article is intended to give you a ten-minute low impact education on what is needed to start up your darkroom to make platinum prints. If you want to search more, I’ve enclosed a list of books on the subject, and a few more specialized web sites to surf. Even though this process is about 130 years old, there is continuing interest in these processes. New books, new web sites, workshops and personal instruction on platinum printing are showing up on a routine basis. This is a quick start. You need to decide if you want to continue. Good luck to you.
Books (It’s like somebody downloaded a web site and printed it out for you!)
Here is what I have in my library of alternate printing books. There are more out there if you look!
Where I have been on the Web
http://www.mikeware.demon.co.uk/ Mike Ware’s alternate process home page.
This article is copyright 2002 by Joe Lipka. All rights reserved.