Blueprints and photomechanical prints have been integral tools in architecture, engineering, and industrial design since the 19th century. Their invention revolutionized how technical drawings were reproduced and shared, and their preservation offers insight into the evolution of human innovation. This article delves into the history of these prints, explores best practices for their storage and preservation, and provides guidance on displaying these historical artifacts.
A Brief History of Blueprints and Photomechanical Prints
The term “blueprint” originates from a photomechanical process known as cyanotype, invented in 1842 by English scientist Sir John Herschel. The cyanotype process used photosensitive chemicals to create a white image on a blue background. Architects, engineers, and builders widely adopted the blueprint technique because it was inexpensive and allowed for the accurate reproduction of large-scale technical drawings.
By the late 19th century, other photomechanical processes, such as diazotypes (whiteprints), were introduced. Unlike cyanotypes, diazotypes produced dark lines on a white or light background, making them easier to read and annotate. These processes marked a significant evolution in technical reproduction, providing durable and precise copies for design and construction.
Despite their efficiency, the advent of digital technology in the late 20th century largely replaced blueprints and photomechanical prints with computer-aided design (CAD) and digital plotting. However, these historical prints remain valuable artifacts, offering a tangible connection to past industrial and architectural endeavors.
Preserving and Restoring Blueprints and Photomechanical Prints
Blueprints and photomechanical prints are inherently fragile due to the acidic chemistry used to create them, as well as the quite often thin paper they were printed on. These factors contribute to blueprints becoming fragile as they age, which is why careful handling and storage are of the utmost importance to preserve them. Here are a few key steps to help ensure their longevity:
1. Handling
•Always handle blueprints with clean, dry hands or wear cotton gloves to prevent oils and dirt from causing deterioration.
•Avoid folding or creasing prints, as this can lead to permanent damage.
2. Cleaning
•Use a soft, dry brush to remove surface dust. Avoid using water or cleaning agents, as they can react with the chemistry of the blueprint and cause staining, discoloration and fading. A skilled conservator can evaluate the blueprint to determine what solutions and treatment approaches will be safest and most effective to wash a blueprint if it is needed. If there are damaging tapes or discoloration that need to be removed, consult with a professional conservator to have the blueprint treated. Do not attempt to treat these condition issues on your own. Blueprints are by their very nature fragile and often brittle materials with very sensitive chemistries. A trained conservator can work to help you address condition issues such as removal of damaging tapes, flattening folds and curls in the paper, reducing discoloration and stains, and mending of tears and losses to the paper.
3. Storage
•Store blueprints flat in unbuffered folders or boxes to prevent bending and exposure to environmental pollutants.
•Maintain a stable environment with low humidity (around 30-40% if possible) and a temperature between 60°F and 70°F (15°C-21°C).
•Keep prints away from direct sunlight, which can cause fading and discoloration.
4. Digitization
•Scan blueprints and photomechanical prints using a high-resolution scanner to create digital backups. This ensures that the content is preserved even if the physical print degrades.
Displaying Blueprints and Photomechanical Prints
When displaying blueprints or photomechanical prints, it is essential to balance the desire to place them on display with the need to protect them from further deterioration.
1. Framing
•Frame prints with UV-filtering glass or acrylic to protect them from light damage.
•Use archival matting and backing to prevent chemical reactions that can lead to deterioration.
2. Lighting
•Display prints in areas with controlled lighting, ideally using LED lights, which emit minimal UV radiation.
•Limit light exposure to no more than 50 lux for sensitive prints to minimize fading.
3. Rotation
•Rotate prints on display to reduce prolonged exposure to light and environmental factors. This ensures their longevity while allowing different pieces to be showcased.
Conclusion
Blueprints and photomechanical prints are more than just technical tools; they are historical documents that reflect the ingenuity of past generations. Proper preservation and thoughtful display can protect these fragile artifacts, allowing future generations to appreciate their beauty and historical significance. Whether in a museum, archive, or private collection, blueprints deserve careful stewardship to maintain their place in the history of design and engineering.