A blueprint is a type of paper-based reproduction usually of a technical drawing documenting an object, an architecture or engineering design. The term is now generally used to refer to any detailed plan of a building or object. Blueprints have for thousands of years provided a universal language by which design and construction information is transmitted to the builder, engineer, craftsperson, designer, and others. Blueprint reading therefore refers to the process of interpreting a drawing. An accurate mental picture of the object upon completion can be formulated from the information provided.
While originally blueprints did have a blue background with white lines (as a result of the process used to produce them), subsequent improvements to the copying process involved ammonia and coated papers that react to light. Additional improvements eliminated the ammonia process, leading up to today’s prints. Blueprints are today usually white pages with black or blue lines. Nonetheless, the term has remained with us and probably will remain in use for a long time to come. You may also hear blueprints referred to as drawings, prints, or plans.
A blueprint is a representation of what is to be constructed. It is a drawing of what is to be built. Blueprints, however, are very precise drawings that are exact representations of what is to be built. Obviously, they are drawn much, much smaller than the proposed structure, but they are exact and detailed. Every line on a construction drawing is carefully placed. The relation of a line to another line shows distance.
Blueprints are critical forms of communication that provide a great deal of information. If the prints are not clear enough to read and use, wait until you have better ones or make your own. Otherwise you may encounter serious problems in the course of the project. Use your judgment.
Drawings have little value if they cannot be satisfactorily reproduced. Sets of prints must be provided to building departments (for approvals), as well as to contract bidders, estimators, subcontractors, and others who are concerned with the construction of the proposed building. Original drawings are typically retained by the consultant. There are several methods of making prints; these are discussed below.