Chapter 10
The Colors of Black and White Photographs

This chapter also discusses tinting and age deterioration.

*******

Heterogeneous collections of old photographs appear to be colored predominantly brown, either from intentional processing or from the ravages of age.

Photographs that are not colored by a three‑color photographic process (as opposed to hand tinting) are customarily called black and white, even though they may be tinted or gold-toned or other colors. But anyone who has spent much time searching through assorted old photographs in antique markets is likely to wonder if there ever were any actual black and whites. The common survivors seem to be mostly brown or yellow in varying shades. Some of the reasons for these colors are:
Original images were sepia or gold toned.
Original images were tinted.
Original paper was tinted.
Binder was dyed
Original images were pigmented (e.g. gum bichromate).
Particle size differences in the image from processing variations
Residues of processing chemicals
Faded images.
Stained images.
Yellowed paper.
Aging changes in the binder (e.g. gelatin).

Evidence of deterioration can be a revealing clue to the process by which photographs were made. A comprehensive discussion of deterioration mechanisms is given by Reilly [122].

It was recognized in the middle of the nineteenth century that fading of photographic images on paper was a serious problem. There were many reasons: individual processing variations, chemicals were impure and not standardized, and paper quality was not uniform until Eastman Kodak perfected paper based on wood pulp in 1926. For forty‑five years the dominant printing paper was albumen paper with an emulsion coating made of egg whites.

Considering the sulfur in eggs and the well‑known affinity of silver for sulfur, it is perhaps surprising that any of them have survived. Toning with gold or selenium was commonly used to stabilize images. The effect also somewhat resembled skin tones, but there was no uniformity, since the resulting tint depended on the chemistry of the emulsion as well as the toner. This is true today: the tones may be sepia, brown, warm black, or blue black. If color is used as a recognition aid, these variations can create many problems, yet there are experienced persons who can identify pictures at a glance. This should be amended to read "sometimes". The bulk of surviving 19th century prints are either albumen prints or early silver bromide gelatin prints, so with a little practice a good average is possible.

Color Measurements
It would be very useful to be able to characterize the colors of 19th century photographs in a quantitative system that would provide reliable descriptors. The necessary technology has been available for some years, and apparently all that is lacking for feasibility studies is funding and interest. There are two requirements:

1. The availability of standard specimen photographs representative of each process in its original condition, or as well-preserved as possible.
2. Readily available measurement equipment.

The present advanced state of color photography has made precise color measurements commonplace, but the required equipment is not cheap or simple. A rigorous method of color measurement is the determination of the spectral energy distribution of white light reflected from a specimen mounted in an integrating sphere. The inner surface of the sphere is coated with pure white magnesium oxide, and the illumination is from a standard lamp. The integrated reflected light is analyzed with a prism or diffraction grating, and the results mathematically converted to tristimulus coordinates. The technique is widely used in manufacturing industries such as paints, fabrics, fluorescent lamps, and dyes. In principle there is no technical reason for not applying the method to historical photographs.

Pilling [117] mentions the use of Munsell color chips to characterize the colors of cabinet card mounts. The Munsell Color System is a subjective color matching system that under controlled conditions can give reproducible numbers to three components of color. These are "hue", the dominant color; "chroma", the degree of saturation; and "luminance", the reflected brightness. A photograph consists of mixed shadows and highlights, and different values of chroma and luminance will be obtained from different regions of the picture. One solution is to integrate, or average, the reflected light as mentioned above. Another is to standardize on matching either the densest shadows or the clearest highlights, resulting in numbers that could be referenced by other workers. It would be a more objective and reproducible system of descriptors than the use of arbitrary terms such as "faded yellow", for example.

The Munsell System is discussed in Hunt [78, 71; 122]. The American Society for Testing and Materials (1916 Race Street, Philadelphia, Pennsylvania 19103), publishes a "Standard Method of Specifying Color by the Munsell System", No.D 1535‑68 or later revision. ASTM Standards may be on file in engineering college libraries. The Munsell System of visual color standards is manufactured by Macbeth Division of Kollmorgen Instruments Corporation, 405 Little Britain Road, New Windsor, New York 12553.

Visual Appearance of 19th Century Pictures

In the absence of a quantitative measurement scheme, a practical way to identify unknown specimens is to compare them to published pictures. The best single reference for paper prints is Reilly [122], Eastman Kodak publication G-25, 1986. Bernard [22], Coe & Haworth‑Booth [32], Eastman [47], and Holme [77] also contain high quality color reproductions of some 19th century prints that give a good idea of their present appearance, provided viewing is done in daylight.

Museums and galleries usually have subdued lighting to prevent fading, often by reduced-voltage incandescent lamps whose light is reddish. A case in point was a prominent exhibition at the George Eastman House, of carbon, albumen, and Woodburytypes, all of which showed remarkably similar rose‑brown coloration under protective dim incandescent lighting. It is an inevitable compromise between protective but distortive lighting, and total inaccessibility to viewing. On the other hand, this writer has seen original irreplaceable photographs from the Civil War period exhibited six inches from a forty watt fluorescent lamp. They were nearly completely gone. Ignorance is a terrible thing.

The fading of color photographs has been intensively studied in recent years, and some of the techniques are relevant to black and white photographs. A significant study (Presented at the International Symposium: The Stability and Preservation of Photographic Images, 1982, The Public Archives of Canada, Ottawa, Canada, sponsored by the Society of Photographic Scientists and Engineers.) was described by Sergio Burgie in 1982. The paper was entitled "Fading of Dyes Used for Tinting Unsensitized Albumen Paper".

His results, which unfortunately have not been published elsewhere, were presented in color slides. The work was based on a selection of nearly unfaded albumen prints in the collections of the International Museum of Photography at George Eastman House. The availability of these standards was crucial to the study.

In this case the extent of age changes was surmised by examining margins that were covered by frames or mounts. This study did not make use of quantitative color measurements. No comprehensive references that treat the problem of identification of 19th century photographs by quantitative color measurements were found during research for this volume.

The Art of Tinting

Enthusiasm for Daguerreotypes and calotypes did not submerge the desire for colored pictures. If scientific ingenuity could accomplish a marvel such as fixing images from nature, surely the achievement of color pictures would be just around the corner. It proved to be a long corner, but in the meantime artist's colors were at hand. As Rothery [128] remarked in 1905, "Color photography is, as yet, in the clouds and the brush and palette must still be used." There was a flood of articles on how to color with oils, chalk, and water colors; some typical ones were by Delery [43; 27], Rothery [129], and Nicholson [106]. A detailed account of tinting lantern slides is found in Burbank [28, 148‑159], who writes the following inimitable hint:

"...the cleanest and most useful dabber is supplied to most persons by nature, one that is not likely to wear out or get mislaid, namely, the finger end. Nothing can exceed the evenness of tint which a practised hand can produce by lightly tapping the paint on the glass he is working on, which gradually renders the color even and smooth.

The finger to be selected is that which has the smoothest skin; generally, the third finger of the right hand is the best. The skin has always a kind of furrowed surface, and some artists, hence, rub the end of the finger lightly on a piece of smooth sand‑paper, by which some of the roughness is removed. This cure of the furrows is very temporary; nature, in a day or two, indignant at this treatment of the cuticle, will retort by growing a skin thicker and rougher than at first, so it is better for beginners to use their dabbers as they find them."

Historical research sometimes rewards us with such whimsies. It seems a curious oversight that the Reverend Burbank did not use the term "fingerprint" in his 1891 book. The fingerprint had been used for identification as early as 1858 by Sir William J. Herschel.

A common form of tinting or retouching was found in crayon prints, which are discussed in Chapter 8 and in Appendix II.