Friday, June 7, 2013

Reproduction & Preservation

We have mentioned in an earlier post the relationship between architectural reprographic processes and jazz music in New Orleans. Tulane University's Hogan Jazz Archive retains the blueprint-laden manuscript collection of local musician John Hyman, aka Johnny Wiggs.

For those interested in large format duplication processes, catalogs published by the Eugene Dietzgen Company provide considerable information. Product number 4310B (top image) was a sheet washer for developing blueprints and negative prints in running water. A clamping device fixed the drawing into a near-vertical position for the washing process. Wet prints could be dried on the rack attached to the top of the washer.

Dietzgen vacuum print frames were sold individually (bottom image) or with high power arc lamps (central image). The company recommended the individual print frame for both electric and sun printing. The frame's vacuum pump connected to a rubber blanket designed to keep the sensitized paper and the trace material firmly in position against the glass plate.

When the vacuum print frame was coupled with the lamps, Dietzgen recommended its use for processing Vandykes and Edco process prints. The latter was the company's method of reproducing original tracings by making a Vandyke negative of the original tracing and then placing the intermediate directly atop a sensitized cloth (called Edco Process Cloth) and exposing the sheets to light as one would do in the development of a blueprint. After the Edco Process Cloth was exposed, the technician would rinse it with water, apply a developing liquid, rinse it a second time, and hang the print out to dry.

Companies such as Dietzgen encouraged architectural and engineering businesses to make duplicates of original tracings for preservation purposes: "This is the best insurance known, for the duplicate may be filed away in a vault, or elsewhere, safe from loss or damage by fire."(1)

(1)Catalog of Eugene Dietzgen Co., Manufacturers Blue Print Papers/Drafting Room supplies/Survey Instruments/and Accessories/Measuring Tapes. Chicago: Eugene Dietzgen Co., 1931, p. 33.

Images above:  Catalog of Eugene Dietzgen Co., Manufacturers Blue Print Papers/Drafting Room supplies/Survey Instruments/and Accessories/Measuring Tapes. Chicago: Eugene Dietzgen Co., 1931.
Southeastern Architectural Archive, Special Collections Division, Tulane University Libraries.

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