Diazo Process

diazo process

[dī′a·zō ‚präs·əs]
(organic chemistry)

Diazo Process


the production of images by means of photosensitive materials based on diazo compounds of the diazonium salt type. Diazonium salts are destroyed on exposure to light and form colored compounds (azo dyes) upon interaction with amines and phenols. The diazo process is used extensively for copying blueprints.


Katushev, Ia. M., and V. I. Sheberstov. Osnovy teorii fotograficheskikh protsessov, 2nd ed. Moscow, 1954. Chapter 18.
References in periodicals archive ?
Vellum and Mylar are both semitransparent, which allows the light used in the blueprint copy process (or diazo process) to pass through the sheet and burn the drawing image onto the blueprint paper.
Two duplication processes are commonly used to reproduce landscape drawings in large numbers: the diazo process and the photocopy process.
Supporting the drafting set is the Reproduction Set: Diazo Process, R84689, which provides a capability to produce engineering drawings and prints in the field.
The diazo process differs from traditional blueprinting, which creates a white image on a blue background (see page 122 of the November Sunset).
Diazo process Duplication process used to reproduce landscape drawings in large numbers.