Albumen prints - Technical details
These details are not intended as a practical manual for the process. Full details and practical tips are available in various books on the process or alternative processes generally, particularly 'The Albumen and Salted Paper Book'(1980) by James O'Reilly, available on-line, which is probably the basis of most modern albumen printing. Be sure to read and follow all safety precautions if you attempt any historic processes.
From 1865-1929, the great majority of albumen prints were made using factory prepared albumen paper. The job of the photographer would have started at the second stage below, Sensitising Albumen Paper. Modern printers have to start by making their own albumen paper.
Preparing Albumen Paper
1. Fresh hen's eggs are cracked and carefully separated to remove the yolks, and any other material including blood and the stringy tissue, leaving the clear yolk.
2. Ammonium chloride (other soluble chlorides such as sodium could be used) was added, using roughly 1.5% weight/volume (1.5g per 100 ml of albumen) either as a powder or dissolved in the minimum amount of water.
3. The mixture is beaten to a froth with a fork or blender. The physical beating and the addition of chloride both help to 'denature' the proteins in the egg white, producing a smooth liquid. A small amount of acetic acid may also be added to assist the process.
3. The froth is covered and kept in a refrigerator (not frozen) for 24 hours and then strained through muslin.
4. The clear liquid is kept in a closed container in a refrigerator for around one week to further 'age' and is then ready for use. It should only have a slight smell and may have a small amount of sediment (it it fit to use until it starts to smell very strongly, perhaps after several weeks.)
5. The clear liquid is poured off any sediment through a muslin filter into a tray (a depth of around 2 cm is plenty) and allowed to reach room temperature. It helps to add a little detergent at this point.
6. Any thin, smooth 100% rag paper such as Strathmore Series 500, Cranes Kid Finish, Platinotype or Parchment Wove and Arches Platinotype is suitable. A sheet of paper is lowered carefully onto the albumen, checking for air bubbles and getting rid of any that form.
7. The paper is left floating for1.5 - 3 minutes, then lifted, drained and hung to dry. The bottom edge is wiped occasionally to prevent a build up of material there. The back of the paper is marked to indicate which edge was hung at the top.
8. Dry, sheets are piled and flattened under weight.
For a higher gloss, and more even prints, paper is double coated. Before the second coat, the first must be hardened or it will dissolve. .
The albumen coating of manufactured paper was hardened by storing it in a warm room for six months. Most modern workers use a 70% isopropyl alcohol (propan-2-ol) / water mixture. This must contains the same concentration of ammonium chloride used in the original albumen coating. The paper is immersed in the solution for around 15 seconds, hung to dry and flattened again.
The second albumen coating is applied in the same way as the first (steps 6-8), hanging the paper to dry by the opposite edges. The paper will keep for months or years, but should be stored overnight in a fairly damp place before sensitising.
Sensitised albumen paper is best used as soon as it is dry, and loses speed and density if kept, so photographers usually on sensitize the amount they need for the day's printing.
1. The sensitising bath is 12% silver nitrate and is used in a glass tray. For small batches of paper it may be more convenient to sensitize paper by brushing with a stronger silver nitrate solution.
2. Working in darkroom safe lighting or very dim tungsten light, float each sheet of paper for 2-3 minutes, then lift, drain and hang to dry. Add the calculated amount of replenisher – 24% silver nitrate - after every few sheets. For each 8x10 sheet floated, 1 ml of replenisher should be added. Blot the bottom edge of the drying sheets frequently to prevent build up.
3. After all sheets have been sensitised, replenish as necessary and then return the silver nitrate solution to its bottle. The bottle should contain around 15g of kaolin (fine clay) per litre of silver nitrate, and should be shaken to help the clay absorb organic material which otherwise blackens the solution rendering it unusable. Leave the bottle to settle and decant the solution carefully when next it is used.
1. The negative or plate to be printed is placed in contact with the paper, held together using a printing frame or vacuum frame etc. These allow part of the backing to be hinged back to check exposure while holding negative and paper in position.
2. The sun or any UV light source is used to expose the paper through the negative. Printing times vary depending on negative, sensitised paper and light source but are usually between 10 mins and several hours. Printing is continued until the darkest areas of the print (or the borders) show some 'bronzing' (a metallic sheen.) Prints get lighter during processing.
1. The print is taken from the frame in subdued light and washed in running water until the wash water shows no sign of cloudiness.
2. Prints are toned in a gold toner. Toning isn't essential, but untoned prints are a reddish brown; toning adds a little density and gives a more pleasing purple brown colour. Considerable experience is needed to judge the best time for toning, as the print changes colour during washing and drying..
3. Prints are rinsed in a few changes of water, then fixed in a weak (15%) sodium thiosulphate fixing bath, made slightly alkaline by a pinch of soda. It is best to use a two-bath sequence, changing the solutions regularly, using each for 4-5 minutes.
4. A washing aid, such as 1% sodium sulphite used for 5 minutes will cut washing times and remove more fixer.
5. After using the washing aid, prints need at least 30 minutes washing in frequent changes of water. Without a washing aid at least 60-90 minutes is needed.
6. Prints are squeegeed and hung to dry, when their final colour and density is clear. They need flattening after drying.