Whiteprint describes a document reproduction produced by using the diazo chemical process. [1] . It is also known as the blue-line process since the result is blue lines on a white background. It is a contact printing process that accurately reproduces the original in size, but cannot reproduce continuous tones or colors.

The meaning of DIAZOTYPE is a photograph or photocopy produced on a surface (as paper) by coating with a solution containing a diazo compound that is decomposed on exposure to light, the compound in the unexposed parts being then converted to a colored image formed by an azo dye by developing especially with an alkaline solution or gaseous ammonia.

A printmaking technique initially developed as an alternative to the blueprint, which it ultimately replaced, for the reproduction of maps, plans, etc. An image is projected onto paper that has been photosensitized with diazonium salts, and then developed with photographic chemicals.

Oct 11, 2021 · Diazotype is an imaging technique which was used until the 90s of the 20th century for producing copies. From the chemical point of view, this technique is based on the photosensitivity of diazonium cations and the synthesis of azo dyes.

May 8, 2019 · The diazotype process is known by several names including diazotype, ozalid, and whiteprint, and can be found in many colors ranging from magenta, maroon, brown, yellow and violet to black or blue.

Mar 12, 2024 · Blueprints are large-format architectural and construction drawings. The original blueprinting process, invented in 1842, involves a light-sensitive chemical reaction to create a negative image (blue lines on a black background), while the modern diazotype method produces dark lines on a white background.

The most common of these is the Diazotype process, refined in the 1920s, which used paper supports sensitized with diazonium salts, a coupling agent, and an acid stabilizer to produce a dark line on a white ground.

Producing a diazotype relies on two basic chemical reactions. First, a diazonium compound (an aromatic ring with two nitrogen atoms) will yield a dye molecule when combined with an

Diazotype. Discovered late in the 19th Century, diazo copies largely replaced blueprints. Sensitized paper and translucent original drawing are exposed to light and ammonia gas. Diazo is inexpensive but unstable. The diazo microfilm process, however, may be stable.

Diazotype is a historical light tracing process which was used, in particular, for reproducing technical drawings. This paper first explains the principle of the diazotype.