Blueprints Used in Manufacturing

In the 1940s blueprints began to be replaced. Blueprints are simple plans used to design products manufactured or built. Some plans are more detailed than others. Blueprints are used to develop and design everything such as: ships, boats, helicopters, guns, cars, games, business buildings, homes, motorcycles, furniture, appliances, and thousands more.

In 1842, a scientific formula consisting of potassium ferricyanide and ammonia ferric citrate was formulated to form a photosensitive compound by Sir John Herschel, a British photographer and astronomer. His formula was used to coat paper that was then exposed to strong light that will convert to insoluble blue ferric ferrocyamide called Persian Blue. The paper is then washed in water to leave a light-stable print. In the beginning linen was used but proved to be unstable because of shrinking. Later on imitation vellum became popular but gave way to the use of mylar.

A glass font is used with a wood frame that contains a spring loaded back. Each plan or drawing is traced in India Ink on any tracing cloth or tracing paper. At this time it is exposured to sunlight needing to be left from a few minutes to an hour after which the frame is immediately dipped in water to remove unexposed coating, then dried. This leaves a clear legible drawing copy of white lines on a dark blue background. Copies such as these have unlimited resistance to water and light.

In the 1940's blueprints began to be replaced by white prints or diazo prints, which contained blue line on a white background called blue lines. Today prints are known as Xerographic prints which are similar to a copy machine using toner on bond paper.

There are 9,960,000 Blueprints available on line today. Some are free but many are sold. There are also books available if anyone prefers them.