23.3.

The creation of albumin photographs consists of five steps; mixing of the albumin/salt solution, coating the paper with albumin/salt solution, sensitizing the paper with silver nitrate solution, exposure through a negative, and fixing with sodium thiosulfate. While just about any paper will work, including handmade paper from Chapter 14, I recommend a good-quality, smooth-textured watercolor paper.[1] You will also need a dozen raw eggs, some table salt (sodium chloride), white household vinegar, silver nitrate, sodium carbonate, and sodium thiosulfate.

To make the albumin/salt solution, you need to separate the yolks from the eggs. One egg at a time, separate the yolk from the whites using your favorite method and place the egg white into a cup. If any egg white is contaminated by yolk, discard the whole egg; egg yolks contain sulfur, which will degrade the quality of your print. Examine each egg white and remove any dirt or bits of eggshell. Once an egg white is free of debris, pour it from the cup into a one-pint glass jar. Continue separating eggs until your jar contains a dozen clean egg whites. To your jar of egg whites add 12 mL of white household vinegar and 12 g of sodium chloride. Put the lid on the jar and shake it until a good head of froth develops. Allow the froth to rise to the surface and then remove it with a spoon, as shown in Figure 23-1(R), leaving clean, clear emulsion in the jar. The emulsion may be prepared in advance and stored in the refrigerator indefinitely. If the emulsion becomes dirty after repeated use, simply shake it and spoon off the froth; most of the impurities will be caught in the froth. A dozen eggs produce enough emulsion for very many prints.

Figure 23-1. Making the Albumin/Salt Emulsion

When you are ready to coat your paper, remove your albumin solution from the refrigerator and allow it to warm to room temperature. Cut your paper to a convenient size and fold up about 1 cm along each edge of the paper. The effect is that you are forming your paper into a shallow dish. You will need to fold the corners in so that all four edges stand up; do not cut the corners; your paper dish needs to be water-tight. Using a medicine dropper or transfer pipette, withdraw some emulsion from your jar. By putting the tip of the pipette well below the surface, you can extract very clean emulsion, free of bubbles and froth. Deliver the emulsion to your paper dish and continue adding emulsion until the bottom of your dish is covered. You can rock your paper dish from side to side and move emulsion to dry areas with your pipette. The goal is to completely cover the paper with clean, bubble-free emulsion. Once the bottom of your paper dish is completely covered with emulsion, allow it to sit for 3 minutes. At the end this time, use you pipette to return the remaining emulsion to the jar.[2] Then fill your pipette with fresh emulsion and use it to wash any bubbles or dirt from your paper, as shown in Figure 23-2(R). Allow your coated paper to dry overnight; you may lean it vertically against a wall, stand it up in a lab drawer or cabinet, or hang it from a line with clothes pins. Coated paper may be stored indefinitely.[3]

Figure 23-2. Coating the Paper with Emulsion

Paper should be sensitized in dim light; a 15-watt incandescent bulb or darkroom safe-light may be used. To sensitize your paper you will coat the bottom of your paper dish with silver nitrate solution using a medicine dropper or transfer pipette. However, you should use a different pipette from the one you used for the emulsion to avoid cross-contamination. You should also wear rubber gloves if you don't want your hands blacker than charcoal. The sensitizing solution consists of 30 g of silver nitrate dissolved in 250 mL of water. It may be stored in a brown glass bottle. Paper should not be sensitized, however, until you are ready to use it. To sensitize your paper, pipette enough silver nitrate solution into your coated paper dish to completely cover the bottom. Rock the dish from side to side and use your pipette to move the silver nitrate solution onto any dry areas. Once the bottom of your paper dish is completely covered with silver nitrate solution, allow it to sit for 1 minute. At the end of this time, use your pipette to return the remaining solution to the bottle, as shown in Figure 23-3(R). Stand your sensitized paper vertically against a wall or hang it from a line to dry in the dark for 1 hour. While you are waiting for your sensitized paper to dry, you may coat more paper with emulsion.

Figure 23-3. Sensitizing the Emulsion

You will need a negative through which to make your exposure. Since you will be making a contact print, the finished print will be the same size as your negative. While you may use a 4x5 inch photographic negative, you may also print a digital image onto transparency film or even onto paper. Most image-manipulation computer programs have an option to produce a negative image. A high-contrast image works best, that is, one with very black blacks and very white whites.

You will also need a printing frame to make your exposure; a standard picture frame works well. The negative and the sensitized paper must be loaded into the printing frame in dim light, the same light you used for sensitizing your paper. Place the negative against the glass of the picture frame. Flatten out your sensitized paper dish and place the sensitized side of the paper against the negative. Then assemble the back of the picture frame so that the negative is held tightly against the sensitized paper so that it holds the sensitized paper tightly against the negative.

Figure 23-4. Exposing the Print

Figure 23-5. The Finished Print

You are now ready to make your exposure. Take your printing frame out into bright sunlight. On a cloudy day, bright artificial light may be used. The frame may be set under a bright lamp or it may be placed face-down on an overhead projector. As the exposure proceeds, the areas of your print not masked by the negative will start to darken, as shown in Figure 23-4(R). Particularly watch the exposed area around the edge of the negative. When these exposed areas turn a rich chocolate brown, the exposure is complete. This may take only a few minutes in bright sunlight or as long as an hour under reduced lighting conditions.

Returning to dim light, remove the paper from the printing frame. You should now see an image on the paper; the areas masked by the negative will still be white, while the exposed areas will be dark brown or black. If you were to turn on the lights now, the entire print would quickly turn black. Soak your print for 5 minutes in plain water and then 5 minutes in fixing solution. The fixing solution consists of 2 g of sodium carbonate and 150 g of sodium thiosulfate (aka sodium hyposulfite) in 1 L of water. Whereas only one side was treated with albumin and sensitizer, the whole print needs to be immersed in the fixing bath; you need to remove any silver which may have soaked into the paper. Finally, wash your print for 30 minutes in running water and hang your print on a line to dry. If you reinforce the folds you made at the beginning, the paper will be less likely to curl as it dries.

With this brief introduction to photographic processes, a whole world of alternative processes opens up to you. You may be interested, for example, in the cyanotype, or blueprint, an iron-based photographic process pioneered by none other than John Herschel. You may be interested in the gum-bichromate process, a color process based on the interaction of chromium compounds with ordinary water colors. These alternative processes have experienced a boom among artistic photographers in recent years. If you would like to experiment with them, see, for example, References [84] and [82].

ImportantQuality Assurance
 

Include safety information in your notebook on the materials you used in this project. Outline the steps you used and tape your finished photograph into your notebook. A true photograph will sport a sharp, well-defined, and permanent image.

Notes

[1]

I use Canson Montval 90 lb. Watercolor Paper. Many papers will work but the best results are to be had from paper that is heavy, smooth, and well-sized. I typically cut paper to 5x7 inches as a matter of convenience.

[2]

It is possible to reuse all three solutions used in this project—the emulsion, the sensitizer, and the fixer—provided that they are not mixed with one another. The emulsion doesn't go bad if refrigerated, it just gets used up. The sensitizer may become depleted after prolonged use; when prints fail to darken in sunlight, it is time to replace the sensitizer. The fixer will also weaken with prolonged use; when fixed photographs darken with time, it is time to replace the fixer.

Spent sensitizer and fixer may be recycled to reclaim their silver content. If you have no access to a commercial recycler, these solutions may be evaporated to dryness and then smelted by the procedures of Chapter 9 as if they were ores of silver.

[3]

In a classroom situation, there are several ways to work around this overnight drying period. First, you may coat your paper with emulsion one week, sensitize and expose it the following week. Second, you may use paper coated by another student the week before and then coat paper for future students while you are waiting for your sensitized paper to dry. Finally, your instructor may have made up coated papers in advance. Ask your instructor which option is best for you.