By ELMER EUSMAN
The holdings of the Library of Congress include a vast collection of original comic drawings, political cartoons and caricatures from America and Europe that span three centuries. One of the highlights of this collection is a drawing by Joseph Keppler, who was a 19th century cartoon and caricature artist and a founding member of the influential American satirical political magazine Puck.
The importance of the 1878 Keppler drawing lies in its subject matter. It features the editorial board of Puck at a time when the popularity of the magazine was at its peak.
The drawing is part of the Art Wood Collection in the Prints and Photographs Division, which was acquired by the Library in 2003. The Library is planning to celebrate the acquisition of the collection with an exhibition in 2005.
Like all objects scheduled to be displayed, the drawing was photographed and then examined by conservators to determine whether it needed treatment before it could safely be exhibited. The sketch was originally drawn in carbon ink on four separate pieces of paper, which had been added to correct or adjust the overall composition of the drawing. Over time, the individual sheets had discolored to various degrees. The overall unity of the drawing, which was clearly meant to be viewed as one image, was therefore affected by the differences in tonal values of the four pieces of paper.
After testing the drawing to determine the solubility of the ink and avoid any unwanted changes to the paper, the conservator decided to separate, wash and, if necessary, bleach the paper to return it as closely as possible to its original appearance.
The four individual paper pieces were separated by carefully wetting the paper and soaking the adhesive to the point where it could be manipulated without damaging the paper. Immediately following the disassembling of the drawing, the four pieces of paper were washed in filtered water. The drawing's carbon ink was not water soluble, so this procedure posed no danger to the medium. After washing and drying the papers, the paper containing the main portion of the drawing was still darker in color than the other three papers.
It is possible in paper conservation to lighten papers by using different bleaching techniques. To recreate the visual unity of the drawing, the conservator decided to brighten the darker paper with a light bleaching process. For this procedure, the drawing is placed in a small amount of water and exposed to an array of lights for a period of time, which varies depending on the severity of the discoloration.
In the case of the Keppler drawing, since the discoloration had not diminished after two hours, a solution of hydrogen peroxide was added to the water in an attempt to accelerate the bleaching process. After 15 minutes the paper started displaying phenomena that can only be described as a conservator's worst nightmare: that is, changes occur that were neither revealed in testing nor otherwise anticipated. In this case, the phenomena—never before seen in the treatment of a cartoon at the Library—consisted of areas of what seemed to be severe discoloration beginning to appear in areas that had previously showed no color. The drawing was immediately removed from the bath, but the newly developed color remained in the paper. Further washing or bleaching did not diminish the new colorant. Alternative bleaching agents had no effect, or worse, increased the "discoloration."
Close examination of the discolored areas revealed that some of the color showed up in larger size tonalities, such as those found in watercolor paintings and drawings (washes). Other areas, such as the now visible image of wood paneling on the back wall and the ceiling in the drawing showed photographic detail. It was this last observation that gave the conservator a clue about the nature of the colorant, which was discovered to be silver. It turned out that the drawing had been executed on top of a photograph.
This is a historic drawing technique, in which a lightly developed photo serves as a guide for the draftsman. After finishing the drawing, the artist treats the paper to remove any traces of the photograph. Because Keppler had not used a fixative properly after this procedure, the light bleaching in the conservation treatment actually caused the silver in the photographic paper to be redeveloped, resulting in the reappearance of fragments of the photographic image. Verification of Keppler's use of this technique was found in a photograph in the collection of the New York Public Library on which his drawing is clearly based. In comparing the two images, it is interesting to observe how much artistic freedom Keppler took in translating the photograph into his drawing.
Once the colorant had been identified, the conservator could design an appropriate treatment protocol. Photographic silver can be "bleached" by using various chemicals, including potassium ferricyanide. A solution of this chemical was tested on a small area of the drawing and proved to be successful in "removing" the colorant by changing the chemical nature of the silver. However, in consultation with the curator in charge of the Art Wood Collection, it was decided to leave the now visible silver as evidence of the technique Keppler used to create the drawing.
The drawing was then reassembled and stored in a temporary housing where it will remain until it is time to prepare the drawing for exhibition in 2005. Visitors to the Art Wood exhibition next year should look for this drawing to see if they can discover the now visible wood paneling in the background that was part of the original photograph.
Elmer Eusman is the assistant to the director for preservation in the Library's Preservation Directorate.