Blueprints are developed using which process?

Blueprints are developed using which process?

• A. Diazo
• B. Inkjet
• C. Photocopy
• D. Heliographic

Answer: (A)

Blueprints come from the diazo process. In this method, a sheet is coated with a light-sensitive diazo compound. The drawing is placed on top and exposed to light; the exposed areas develop into a blue background while the drawing lines remain white. After washing away the unexposed chemicals, you’re left with white lines on a blue field—the familiar blueprint look. This method was widely used because it could cheaply reproduce large-scale drawings for architects and engineers.

Other options aren’t used to develop traditional blueprints: inkjet prints the image with ink on paper, which isn’t the classic blueprint reproduction; photocopying uses toner to create copies on white paper; heliographic is an older sun-based photographic process not associated with producing blueprints.