Letterset

The Letterset is a high-pressure process .

In this process, the parts to be printed are raised in the printing form. However, the printing takes place from the printing block onto a rubber blanket cylinder before it is transferred to the printing material. For this reason, this type of printing is also called indirect letterpress . The name is made up of letterpress (English book printing) and offset (transfer printing using rubber cylinders).

In the letterset, the correct way round or a thin wrapping plate, often a photopolymer plate, is required. These clichés must be made to measure with regard to the plate thickness, since the blanket cylinder no longer requires adjustment, as is customary in letterpress printing. The printing inks are highly concentrated and have a high viscosity.

The areas of application of the letter set are in the printing of packaging material for larger formats, forms and securities, but especially in the molded body area (cups, tubes, cans) and when printing CDs and DVDs . One disadvantage is that finer screens over 60 lines / cm can be reproduced poorly. In document printing, it is advantageous to a certain extent that, due to the absence of dampening, “bleeding” dyes can be used in the printing ink.

This process is often incorrectly referred to as dry offset. This can be explained by the fact that the printing takes place via the blanket cylinder and can also take place in an offset printing machine provided for this purpose with the dampening switched off.

literature

• Hiller, Helmut and Füssel, Stephan: Dictionary of the book . 6th edition. Frankfurt am Main: Vittorio Klostermann Verlag, 2002. ISBN 3-465-03220-9
• Liebau, Dieter and Weschke, Hugo: Polygraph specialist lexicon of the printing industry and communication technology . Frankfurt am Main: Polygraph Verlag, 1997.