The 'Chicago House Method' and Digital Epigraphic Recording
Founder James Henry Breasted committed the Epigraphic Survey to the preservation of Egypt's cultural heritage by non-destructive means: through documentation so precise it could stand alone as a replacement in the absence of the original monument. Large-format photography (8x10, 5x7, and 4x5 inch negatives) is an essential tool in this process, and one of the first goals of Chicago House was to create a photographic archive of as many of Egypt's accessible standing monuments as possible, photographed inside and out. Breasted understood, however, that photographs alone cannot always capture all the details of the often damaged or modified wall scenes of individual monuments, since the light source that illuminates also casts shadows that obscure details. To supplement and clarify the photographic record, precise line drawings are produced at Chicago House that combine the skills of the photographer, artist, and Egyptologist.
First the wall surface is carefully photographed with large-format film and digital cameras whose lenses are positioned exactly parallel to the wall to eliminate distortion. From the negatives, which are now digitally scanned and duplicated, photographic enlargements were produced, printed on a special matt-surface paper with an emulsion coating that can take pencil and ink lines. This is now also accomplished digitally (see below for more details). An artist takes the enlarged photographic print (hard copy or on a digital drawing tablet) to the wall itself, and pencils directly onto the photograph with pencil or stylus all of the carved detail visible on the wall surface, adding those details that are not visible or clear on the photograph. Then, in the studio, the penciled lines are carefully inked with a series of weighted line conventions to show the three dimensions of the relief, with damage that interrupts the carved line rendered with thin, broken lines that imitate the nature of the break. In the case of hard-copy drawings, when the inking is complete, the entire photograph is immersed in an iodine bath that dissolves away the photographic image, leaving just the ink drawing. In the case of digital drawing, the digital photographic reference layer on the drawing tablet can be removed or brought back at any time. Copies of the drawing are printed in blue and divided into sections against a white background. These "collation sheets" are taken back to the wall where the inked details on the 'blueprint' are thoroughly examined by two Egyptologist epigraphers, one after the other, who pencil corrections and refinements on the blueprint with explanations and instructions to the artist written in the margins. Digital collation sheet notations are made directly on the drawing tablet. The collation sheets are then returned to the artist, who in turn takes them back to the wall and carefully checks the epigraphers' corrections, one by one. When everyone is in agreement, the corrections are added to the inked drawing, the transferred corrections are checked for accuracy by the epigraphers, and the drawing receives a final review by the field director back at the original wall.
Consultations between artist, epigraphers, and field director, the consensus of all skill sets combined, ensures a finished facsimile drawing that is faithful to what is preserved on the wall in every detail. This is the essence of what is referred to as the "Chicago House Method." The corrected ink drawings, photographs, scans, text translations, commentary, glossaries, and duplicate negatives are then taken back to Chicago for processing and publication in large folio volumes for distribution worldwide. These publications are available for sale in hard copy and now also for free distribution in electronic format, part of a new program recently inaugurated by the Oriental Institute, and generously funded by OI Advisory Council Members Lewis and Misty Gruber.
In some instances, it is not possible to photograph the surface that is being recorded, or to observe it directly, since the stone in question is masked by an adjoining architectural feature. For such cases we have developed a special method of recording by indirect observation. Sheets of aluminum foil are inserted into the interstice and used to make rubbings of the carved surface, a labor-intensive process that results in the extraction of enormous amounts of completely hidden carved information. The impressions thus produced on the foil are then slipped beneath sheets of clear diacetate and traced as if they were the original surface of the block. Once a field drawing on diacetate is completed, the artist copies the original tracing onto another piece of diacetate in the studio in order to refine the ink lines of the original. At this stage the drawing, still at one-to-one scale and thus potentially rather unwieldy in size, is submitted to the photographer, who makes digital photographs of the drawings at a high enough resolution to ensure clear reduced printouts. These printouts are used by the epigraphers as collation sheets. In addition to collations of the drawings, the epigraphers also make notes on the content and condition of the reliefs, as well as measured isometric drawings of the blocks on which they occur. After the collation is completed, the epigraphers and the artist examine the block together to consider the suggested corrections and to reach an agreement regarding the changes to be effected on the drawing. In the last step of the field process, the field director makes a final on-site check of the corrected drawing. The diacetate is then scanned, reduced to scale, and digitally inked using the normal Chicago House drawing conventions. This method produces the most accurate possible copies of inscribed surfaces that cannot be seen by eye or camera, and would otherwise escape documentation.
Digital Epigraphic Recording
Recent advances in computerized drawing equipment and graphics software now make it possible to perform all stages of the Chicago House Method using digital technology. In the updated version of the Chicago House Method, scanned photographs and digitally generated othomosaic photographs are used by the artist to digitally pencil the essential outlines and details of each scene or text by direct observation of the original on a digital drawing tablet with a digital drawing stylus. The digitally penciled enlargement is then used as the background for the digital “inking” layer of the sun-and-shadow lines. The artistic conventions used for raised and sunk relief, traces, damage, plaster, and other features of the decorated surface remain the same, and the care and skill required of the artist are as great as those required for inking on paper, but the digital drawing gives a greater flexibility in how the “inked” drawing can be manipulated, allows the transfer of the information in multiple scales and formats, and makes any necessary corrections go much more quickly. Collation sheets can be printed directly, avoiding the necessity of using (now hard to find) blueprint paper, and prints of the facsimile drawing in whole or in part can be used for a variety of other field research purposes as well. All digital files are carefully backed up in multiple locations, ensuring the security of the data, which adds an important archival loss-prevention component to the methodology. Then, when the drawing is complete, having undergone the same series of wall checks outlined above, it is already in digital format, and thus ready to be sent directly to the publishers for layout, avoiding the need for costly and technically difficult scanning of inked enlargements. This digital modification of the traditional Chicago House Method is now fully in place, thanks to generous grants from the Women’s Board of the University of Chicago and Dr. Marjorie M. Fisher, which have permitted the purchase of the necessary high-end tablets and computer systems. Digital epigraphic recording promises both to open new possibilities in terms of the accuracy of our recording and the breadth of information that can be captured, and to streamline our documentation process at a time when the need for rapid salvage of the threatened monumental material is increasingly urgent.
For additional details about the digital recording techniques now utilized by the Epigraphic Survey, see the web site digitalEPIGRAPHY, masterminded by Chicago House senior artist for digital drawing Krisztián Vértes: