История письма и чтения. Асафова Г.К. - 132 стр.

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Lübeck (1475), the head of the Hanseatic League. From there, printing spread to

Denmark, Sweden, Rostock, Danzig, and Russia, though the first printer who went

to Russia was apparently murdered before he could achieve anything. Printing first

began in Russia in 1552, with the help of a printer from Copenhagen.

MODERN PRINTING TECHNIQUES

Electrostatic printing

Electrostatic printing is a process of printing without contact, without a type

form, and without ink. The paper is coated with a very thin layer of zinc oxide,

which makes it an insulator while in the dark and a conductor of electricity when

exposed to light. This paper is given a negative electrical charge in the dark. It is

then exposed by light projected through a positive film of the document to be

reproduced. The zinc oxide layer becomes conductive wherever it is illuminated,

and the negative charge is dissipated in those areas that correspond to the blank

surfaces of the document. Finally, the paper goes through a bath containing

pigmented particles that are attracted by what remains of the negative charge and

are fixed by drying.

Electrostatic machines have been designed for printing geographic maps.

These are composed of five successive units, each carrying out the same complete

cycle of processing the paper to produce an edition in five colours at speeds of

about 2,000 copies per hour. Improvements in the bath of pigmented particles are

making possible the application of the electrostatic process to printing small books.

Printing inks

Printing inks contain three components: the vehicle, the colouring

ingredients, and the additives. The vehicle, responsible for transferring the

colouring ingredients from the ink fountain to the type form, can be either a

vegetable base (linseed, rosin, or wood oils), which dries by penetration and

oxidation and at the same time ensures fixation, or a solvent base derived from