Diazo Machine, Continued
Diazo material is stored on a first in/first out basis. Before storing, mark the
contents of the package with the date received and package contents. Diazo
materials are light and temperature sensitive. Store them in a cool, dark, dry
Master artwork for diazo reproduction are dense, opaque images on a
transparent or translucent base of paper or acetate. A commercial product,
called transparentizer, lessens the opacity of lightweight translucent
papers. When creating the master, use shading sheets judiciously; the heat of
the mercury-vapor lamp in the diazo machine can melt the adhesive. It will
also melt a master created using an image from a thermal copier. Place
registration marks outside of the image area in multifoil transparencies.
To expose diazo material, place the sensitized material on the feedboard
emulsion side up and place the master on the material emulsion side down.
Better images result from emulsion to emulsion contact. Webb belts will
slowly feed the combination through the machine. There is a slight
dimensional instability in diazo material that occurs as the cylinder rotates the
diazo material from the heat of exposure to the dampness of the development
process. The master and the material will automatically separate before the
material enters the development area.
Figure 4-6 illustrates placing a master on diazo material.
Figure 4-6. Combining a master with
diazo material to feed into the machine.