The intent and methodology of this manual
This book is intended for anyone who has architectural plans, whether a group of 20 or 200,000. The manual is designed to be used by individuals with no special training in preservation, photography, or architecture. In writing a book for non-specialists or professionals with no access to facilities for chemical analysis, we purposely set for ourselves the task of determining a method of identification based solely on visual examination. The scope of this inquiry covers reproductions which were commonly used in North American architectural practice from 1860 to approximately 1960. Photographically produced reproductions are the core of our research. Unlike ink or carbon based copies many of these prints are similar to photographic images and have special preservation needs. The first step in preserving photo reproductions is identification. To preserve the prints which remain in existence it is necessary to identify them in order to determine which measures will affect their long term conservation.
We have designed the manual with a flowchart and twelve comprehensive chapters on individual reproductive processes. The organization of these two sections allows the user to move easily between them while working with an actual print. A glossary and a classified bibliography are included. Additional information relating to the care of architectural drawings and prints is included in the appendices.
The flowchart presents a series of questions to be answered, based on an examination of visual criteria, which lead to a tentative identification. The criteria include characteristics of the support, the image, the surface, and the overall condition. No one factor can be used in making a conclusive analysis. Prints can be examined in normal lighting conditions, preferably filtered for ultraviolet light. The use of a magnifying loupe of 10x to 30x is recommended. To acquaint the reader with the specific terminology used in our methodology a glossary of terms is included. It is suggested that this glossary be reviewed before beginning to use the manual. All of the terms included in the glossary are italicized in the body of the text, at the first instance in each chapter, for reference. With practice, a user will be able to dispense with the flowchart and go directly to the chapters to confirm identification.
Once a print has been tentatively identified, the next step is to read the chapter pertaining to the specific process. It will allow confirmation of the identification, as well as provide recommendations on measures that can be taken to preserve the print. The chapters are separated into two parts, photographically produced prints and photomechanically produced prints. These categories separate prints which have residual chemicals in their makeup and prints which are made with nonreactive carbon, ink, and dyes. This distinction will directly affect the prints' long term conservation.
This manual details twelve distinct processes and has additional information on several others. Some of the processes have broad variations so it is important to confirm the identification with the complete information available in the chapters. There were many other processes in use during the period of time which our research covers and the possibility exists that a print may be discovered which does not fit into any of the described reproductions. If identification cannot be confirmed, isolating the print in an open polyester sleeve and keeping exposure to light at a minimum is the safest course of action.
Each chapter is laid out, in this order, dealing with the following aspects of photoreproductions:
- History and use
- Manufacturing process - Degradation and storage
The first three sections are designed to enable the reader to identify the process by which a specific print was produced. Visual clues to identification include the nature of the support, the color of the ground and the lines, the characteristics of the line, the characteristics of the surface of the print, typical degradations and trade names that were used which might be seen on the verso of the print.
The fourth and fifth sections provide information on the history of each type of print, its use within architectural firms, and the process which was used to manufacture it. Understanding the technique used to produced a print can provide insight in the examination process and aid in identification. The manufacturing processes are described in terms that will hopefully allow a reader to comprehend the technique without any specific knowledge of chemistry.
The last section details degradations which may already be present or degradations which could possibly occur under specific circumstances. Storage and handling procedures are suggested for each type of print, in relation to the specific degradations induced by its makeup or by contact with adjacent documents.
We advocate a conservative approach to housing; when in doubt, isolate to eliminate the risk of contact degradation. The knowledge derived from this manual can enable the custodian of architectural plans to execute further conservation measures for their holdings.
At the end of each chapter are illustrations of representative prints which correspond to various aspects of identification. There are full views and highly magnified views of each type of process as well as some illustrations of typical degradations. Not every print will appear like those in the illustrations. Variations in manufacture and storage conditions will affect their current appearance. In conjunction with the flowchart and the chapters, the illustrations can assist the reader in deriving a conclusive identification.
Cautions and suggestions
Misleading factors in identification include: commonly used names and trade names; odor; the date which may be found in the image of a print.
Names by which reproductions are called in the trade are frequently used for more than one process. The section on synonyms includes notes on these overlaps; trade names are identified by quotation marks.
While some documents have a characteristic odor, the smell can transfer to almost all neighboring documents, making it difficult to discern which of many prints may be the original culprit.
The date which appears in the reproduction is often a misleading factor in identifying a print. Unless a date is handwritten or stamped onto the print, the date written on the original drawing, which is reproduced in the print, could possibly be years apart from the time the print was made. The date of the original drawing allows us to determine only that the print was made after that date but not necessarily on that date.
Several appendices have been included to assist the reader in caring for collections of architectural drawings and prints. A classification chart of the processes in the chapters gives a comparative overview. A few other types of copies which may be found in architectural plans collections are briefly described. There is a section on recommendations for exhibition and handling and a brief synopsis of storage recommendations for architectural plans. Appendix 5 includes a report on the reproduction processes which are currently available for large format architectural plans and recommends the most appropriate means for copying documents from historical architectural archives.
Prints will be found in a variety of conditions. We have purposely not commented on conservation treatments. This area is expressly the concern of trained professional conservators. This manual attempts to assist the custodians of architectural archival holdings in making appropriate choices. As preservation concerns arise (such as reformatting), the identifications concluded from this manual will allow caretakers to make more informed decisions.
The proper identification of photoreproductive prints, and the knowledge of their constituent elements, is a crucial component of every aspect of the preservation of architectural collections: records storage, access, exhibition, duplication and conservation. Knowing what a print consists of determines its use and care; it is thus important to understand how reproductions are produced and should be cared for. They are frequently the only documents that can relate the history of architectural structures.