Albumen print

The albumen print is the commonest photographic object a reader will ever be asked to identify or store, and it is the best argument in the course for treating the binder as part of the chemistry rather than as packaging for it. Change nothing but the layer the silver sits in, and the sharpness, the surface, the highlight colour and the failure mode all move together. Albumen’s own page carries the material; this entry carries the process.

The chemistry

It is a salted paper print with a better surface, and the difference is one of position rather than of reaction. The salting solution goes into the egg white before the coating, so the chloride is inside the binder, and the silver chloride therefore forms in the albumen layer rather than in the paper fibre. The AIC’s identification note gives the image layer as photolytic silver on an albumen binder, colloidal rather than filamentary.

The reaction is the same double replacement the whole silver-chloride family runs on, with the cation as a spectator. Reilly is explicit about which chloride the trade reached for: ammonium chloride was the most commonly used in the nineteenth century, dissolved in a minimum of water and added to the egg white before the beating. His figures hold whichever chloride is used — 1 to 1.5 per cent gives a less sensitive paper tending to slightly more contrasty prints from thin negatives, at the cost of a rich dense image; 1.5 to 2.5 per cent is normal; more than is needed “only results in higher silver consumption without conferring any additional benefit”.

⚗Three denaturing treatments, and why none of them is optional

Reilly’s account of preparing albumen is a short course in protein chemistry disguised as a workshop note, and it explains every step of a procedure that otherwise looks like superstition.

Beating. The proteins in egg white have different viscosities, so native albumen is not one substance but several behaving differently. Beating it to a froth and letting it settle back to a liquid denatures them and produces a homogeneous liquid that will form an even layer.

Chloride. The salt is there to make silver chloride when the sheet is sensitised — but the chlorides also help to denature the albumen, and one visible effect of adding them is to reduce the volume of froth produced during beating.

Acid. The third treatment is a deliberate lowering of pH, with acid or with alcohol. The chemical forces which bind together the enormous protein molecules grow weaker as the pH is lowered, and the physical properties change as a result. Native egg white is alkaline at pH 7.8; glossy papers are made with partially decomposed, acidic albumen, which coats more evenly, gives a glossier surface and has less tendency to yellow after sensitisation.

Taken together the effect is, in Reilly’s words, to change the egg white completely and irreversibly. There is no undoing it and no reconstituting the original.

Hardening before sensitising. A freshly albumenised sheet has to be hardened or it dissolves, and the traditional method was to cure the sheets for months. The quick method is a brief immersion in 70 per cent isopropanol, and Reilly is precise about why that number: pure alcohol is too strong and coagulates the layer unevenly, while too dilute a solution is not strong enough to coagulate the albumen before it partially dissolves into the water. He adds a second rule that shows how carefully the bath is matched to the paper: whatever chloride the albumen contains must also go into the alcohol, or the chlorides leach out of the layer.

Historical workflow

Salt the albumen, beat it, let it settle, strain it and keep it cold; float the paper on it; dry; harden; sensitise by floating on or brushing with silver nitrate; dry; print out by contact under a negative in ultraviolet; rinse; tone in gold; fix; wash.

The industry behind that sequence was an agricultural one. Dresden became its centre because it sat close to the sources of raw paper stock and enjoyed an abundant supply of low-cost eggs — and, Reilly notes, lower labour costs than its English or American competitors. The paper itself had to be extraordinary: thin, smooth and of exceptionally high quality, free of the metal flecks that came from buttons left in the rags and from the paper-making machinery, and made with mineral-free water, which in the 1850s only nature could supply. The mill at Rives in France drew its water from a mountain lake fed by melting alpine snow.

🕰The gloss was the point, and it was unpopular

The Getty records that early albumen prints, before about 1870, were usually less glossy than the later double-coated and burnished ones, and that in the 1850s “the glossiness of albumen photographs was highly criticised in the photographic literature”, because the public was accustomed to the matte character of salt prints.

Taste changed; double coating and burnishing pushed the gloss further; and the argument about surface that every alternative printer still has with themselves started here. It is also why matte albumen exists as a separate row in this atlas.

The image

Sharper, glossier and cleaner in the highlights than a salt print from the same negative, and all three for the same reason: the silver is held in a layer on the surface instead of scattered among fibres.

Colour is a rich purplish brown when gold toned. Reilly matches the bath to the paper — 0.4 to 0.5 g of gold chloride per litre for glossy albumen against 0.1 to 0.2 g for the porous matte papers — and warns that too strong a bath deposits gold superficially and the layer is then largely removed in the fixer.

Not every toner works on it. Reilly is emphatic that all platinic chloride formulae, the platinum(IV) salts of De Caranza’s 1856 suggestion, have so little toning energy that they are totally ineffective with albumen paper; the platinous salt is a very active toner in acid and gives brown and brownish-black tones where gold gives purples and blue-blacks.

Permanence

The characteristic failure is yellow highlight staining, and it is not reversible. Reilly’s account is the other half of the silver sulfide page. Albumen binds silver so tightly that hypo does not remove it, so a small amount of silver remains in every area of a fixed albumen print, highlights included — the glossary records Haddon and Grundy’s measurement, an unexposed sheet thoroughly fixed and washed still holding nearly 5 per cent of the silver it had been sensitised with. Labile sulfur, from residual fixer or from the atmosphere, converts that silver to silver sulfide, and that conversion is the immediate cause of the yellowing that disfigures so much nineteenth-century work.

Then the cruelty of it: the sulfide stain is much more chemically stable than the colloidal silver of the image itself, so no known treatment removes the yellowing without destroying the print. Stability is not a virtue when the wrong thing is stable.

The problem was recognised within five years. The AIC records albumen print deterioration referenced as early as 1855, when the Photographic Society of London set up its Fading Committee, and the causes it reported: imperfect washing, an old or insufficiently acidic hypo bath, acidity in the mounting materials, and excessive moisture and sulfur in the atmosphere. Its recommendation was thorough washing and toning with gold chloride — the two controls this course still teaches, arrived at from failures in the field.

One processing detail follows from the binder and belongs here. Reilly adds 2 g of sodium carbonate per litre to his fixing bath to promote more effective fixation and to prevent blistering of heavily albumenised papers; that formula carries the figures and the two-bath procedure.

Hazards

Silver nitrate, named explicitly in the rubric under Level B, at sensitising strength and handled wet.

70 per cent isopropanol as the hardening bath: a volatile flammable solvent in an open tray, which the Level A criteria permit only in small quantities and which is one reason this process sits at Level B rather than below it.

Gold chloride for toning, Level B on its own page, with the reminder that the substance sold as “gold chloride” is chloroauric acid rather than gold(III) chloride and that the two differ by about thirty per cent in gold content.

Ammonium chloride is mild. The albumen itself is a food material and its own page classifies it Level A; an albumenised sheet becomes photographic only when it meets silver nitrate.

Waste is silver-bearing throughout — the sensitiser, the rinse, the toner and the fixer — and belongs to recovery.

Where the course teaches it

Part XXIII, Albumen Printing, which is built as Part XXII with one variable changed — the chloride dissolved in egg white instead of laid on paper — so that the density, the colour, the gloss and the failure mode all move together.

Egg Albumen: A Protein Binder and What It Does to Silver is the lesson this entry most depends on, and its organising claim is that every step of the process is an attack on a named set of proteins with a purpose: the beating, the salt, the acid, the week in the refrigerator. It carries denaturation and why the coating survives a water bath, why the froth is not what you use, what is documented and what is folkloric about ageing and fermentation, the silver–albumen complex, where the gloss actually comes from, and double coating in detail. The sentence to take from it is that the salting is inside the binder, and that is the whole difference.

Lab: Preparing and Coating Albumen Paper is Level A — thirty-five eggs and no silver in the room — and Lab: Sensitising, Printing and Toning an Albumen Print is the Level B half, where three minutes on the silver bath decide what you have.

The Albumen Print as an Object, and How It Decays takes up this entry’s permanence section and sharpens it into a claim a maker can act on: almost every surviving albumen print is yellowed, and the best evidence says that is a property of the material rather than a processing failure — which changes what a printer today should do about it. It also carries cracking, the mount as an agent of decay, and where the storage guidance disagrees with itself.

And the process’s lower boundary is taught in the part before it. Part XXII’s variants lesson sets out the binder ladder and shows that there is no boundary between a salted paper and an albumen print, only a dilution — which is why arrowroot and albumenised salted paper and matte albumen are separate rows in this atlas rather than footnotes to this one.

What was already written and still bears on it: the albumen, silver nitrate and silver sulfide entries, Reilly’s alkaline fixing bath with its albumen-specific carbonate addition, and the troubleshooting atlas, which carries albumen crazing and yellowing as diagnostic entries with confirming tests.