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Architectural reprography , the reprography of architectural drawings, covers a variety of technologies, media, and supports typically used to make multiple copies of original technical drawings and related records created by architects, landscape architects, engineers, surveyors, mapmakers and other professionals in building and engineering trades. Within the context of archival preservation, the custodians of architectural records must consider many aspects of identification and care when managing the artifactual nature of these materials. Storage containers, handling, paper and chemical compositions and interactions, ultraviolet light exposure, humidity, mold, and other agents of potential harm all interact to determine the longevity of these documents. As well, architectural reprographic drawings are often in very large formats, making storage and handling decisions especially complex.

With the rise of the professionalized practice of western architecture in the second half of the 19th century, the field of architectural reprography—and the corresponding developments of photography and mass-produced wood-pulp paper—saw significant experiments and advances in technology. Beginning with major refinements in blueprinting processes in the 1840s, through the widespread adoption of diazotype printing after World War II, the design profession turned to analog architectural reprography to create accurate, to-scale reproductions of original drawings created on tracing paper, vellum, and linen supports. These copies were typically used throughout the architect's own design process and also for distribution to clients, contractors, governmental agencies, and other interested parties. However, the integration of CAD—or Computer-Aided Design—over the last twenty-five years of design practice has made analog reprography far less common in the profession and more ephemeral in n

Both the underlying support—paper or plastic—and the image type are used to identify the specific processes used in architectural reprography. Between the late 19th century and the late 20th century, several processes emerged as the preferred methods, used for decades, while other less common processes were employed for shorter periods of time. Blueprints edit First developed in 1725, blueprinting uses a wet process to produce an image of white lines on a cyan or Prussian blue ground. To make a blueprint, a heavy paper (or more rarely drafting linen) support is impregnated with potassium ferricyanide and ferric ammonium, placed under a translucent original drawing, weighted with glass, and exposed to ultraviolet light. After sufficient light exposure, the glass and original drawing are removed and the blueprint paper is washed to reveal a negative image. This same process, using an intermediary reprographic drawing, could also be used to produce a positive blueprint—blue lines on a whi

Hectographic prints Ferrogallic prints Gel-lithographs Photostatic prints Wash-Off prints Silver halide prints Electrostatic prints

For large collections of architectural materials, conservation work can address several areas of concern. Consultation with a professional conservator is recommended, although some minor treatments can be accomplished by general caretakers with training. Rolled and folded reprography, once cleaned, can be flattened through humidification. Cleaning may be done with white vinyl erasers, using great care in areas of friable media, such as graphite and colored pencil. Tears, losses, and other surface damage should be treated by a professional conservator. For particularly fragile or frequently-handled prints, sheets may be encapsulated in polyester or polypropylene film for additional support and protection. This is not recommended, however, for reprographic prints with annotations in friable media.

Rolled storage edit The most common form of storage for architectural drawings—both for drawings in active professional use and in archival environments—has traditionally been in rolls. While this allows for efficiency in the use of space and ease of retrieval, potentially damaging situations can arise from a casual approach to roll storage. For reprographic drawings on paper supports, rolling can stress paper fibers and make unrolling for examination more difficult. Small rolls can be easily crushed and ends can be creased and torn without additional protective wrapping and support. Flat storage edit In circumstances where fragile, rigid, or otherwise atypical media makes rolled storage unfeasible, storage in flat boxes or flatfile drawers can be the best choice. Acid-free and lignin-free portfolio boxes, ideally no more than four inches deep, can be cost-effective and allow more flexibility in arrangement on shelving. Flatfile furniture should meet the minimum requirements of archiva