Blueprint
Blueprints were first introduced in the 19th century, to allow the reproduction of documents, and in particular drawings used in industries such as construction. Blueprints are generally recognisable from their blue background and light-coloured lines. They create an accurate negative reproduction of the original using a contact print process on light-sensitive sheets. Before this, reproductions were created using a photolithographic process, or by hand-tracing, both of which were expensive and time consuming.
Blueprints were developed in 1861 by French chemist Alphonse Louis Poitevin, who discovered that ferro-gallate becomes an insoluble, permanent blue when exposed to light. If it is coated onto paper (or a similar sheet material such as imitation vellum or polyester film) in an aqueous solution and then dried, (at which point it is yellow) it can be used to accurately reproduce large-scale translucent documents such as drawings.
Reproductions are made by placing the original, translucent document above a ferro-gallate coated sheet in a frame and then exposing them to light. The unconverted coating is then washed away, leaving a stable negative reproduction of the original.
Other photo-sensitive coatings have been developed, along with the similar diazotype or ‘whiteprint’ process (also known as the blue-line process as it produces blue lines on a white background), but it has now been made largely redundant by the development of large format black and white and colour printers. It is still sometimes used to for artistic reasons.
The term ‘blueprint’ can also be used more generically to refer to a design drawing or to a plan for an activity.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- Architectural reprography.
- As-built drawings and record drawings.
- Assembly drawing.
- Component drawing.
- Computer aided design.
- Concept drawing.
- Construction drawing.
- Detail drawing.
- Elevations.
- Engineering drawing.
- General arrangement drawing.
- Installation drawings.
- Manual drafting techniques.
- North American Paper Sizes
- Paper sizes.
- Projections.
- Schematic.
- Section drawing.
- Shop drawings.
- Site plan.
- Technical drawing.
- Types of drawing.
- Working drawing.
Featured articles and news
ECA proposes strategies for the present and the future.
Paul Morrell to lead independent review of the construction products testing regime.
Standard will help employers foster wellbeing and manage psychosocial risks.
The United Nations has approved the IFSS common principles
Global fire standards for safety of people and property.
An introduction to the 5 core principles of lean.
Civil engineers and environmental methods of construction
Can the profession use its skills to save the world from climate change?
How faulty science resulted in sanitation reform.
Conserving the Hilda Besse Building
Improving facilities, accessibility and overall appearance.
BSRIA IAQ topic guide published
Free download of TG 12/2021 available.
Electrotechincal mentors wanted
TESP works with The Youth Group to form skill sharing network.
OpenBuilt supply chain technology in development
Big tech collaborates on platform for the built environment.
Concerns raised over Future Buildings Standard
Letter signed by 21 organisations sent to MHCLG.
The infrastructure planning process
A look at the Government's strategic approach.
Steps to help reduce the spread of infection inside buildings.
Receive the Designing Buildings newsletter
Click the button to subscribe.