Hectograph

As Hektographie (also Hektografie, from Ancient Greek ἑκατόν Hecaton "hundred" and γράφein gráphein " carve, write ", literally " hundreds of letters " about " hundredfold "; similar: Kilo graph or kilo Graf) transfer printing methods are called, with which documents without the use of a press, but could be reproduced by means of a -marking template, the template.

Basics

All methods have the Hektographie is common that a special handwritten ink or an ink sheet or ribbon - is transferred to a usually coated with a special mixture of gelatin paper - for example, by typewriter stop. From that prints are then made ​​by various methods.

Hektographie from the 19th century

Originally, the template has been described the correct side and pulled the trigger on a Leimbett. This took over the ink as a negative. You then If a sheet of paper on the plate and exerts a light pressure, so a sufficient amount of dye is transferred to the paper to provide a very clear copy. But it is so much dye left on the plate in order to make a larger number of copies in succession and without any further manipulations. Finally, can the font of the glue board removed with a damp sponge and use the glue mixture again.

After a patent in 1879 for Kwaisser and Husak the Leimmasse of one part of gelatin, four parts was melted glycerin of 30 ° Be and two parts of water at moderate heat. An alternative method to melt 100 grams of finest gelatine with 400-500 cc of freshly precipitated and still moist sulphate of barytes in a water bath, set under stirring 100 grams of dextrin and - depending on the concentration - 1000-1200 grams of glycerin added, allowed to cool with occasional stirring and pouring the still -flowing mixture into a shallow metal box in which it solidifies.

The to-use inks are composed of one part methyl aniline violet, seven parts distilled water and one part alcohol and two parts acetic rosaniline ( magenta ), ten parts water and one part alcohol. The best ink is a very concentrated aqueous solution of the pure methyl violet or a concentrated solution of eosin.

A special variant of this method was the Hektographenrolle, which was still in use well into the second half of the 20th century, particularly on board cargo ships, because many documents used there differed from the standard paper sizes, and it, therefore, not suitable for other procedures.

20th century

In the 20th century came to precursors that were partly tested before the turn of the century, a process to which ended in the stencil. If the template reversed - as a negative - created, it can be used directly as a deduction submission. For this, a special two-layer stencil was used, in which a color layer on top of the second layer at the locations described with sufficient pressure transmitted the color on the back surface of the top sheet. From these similarly -crafted as the offset laterally inverted matrix, which is spanned with most devices on a crank- powered roller, can be granulated by wetting with a color -solvent (eg, alcohol / spirit) in an - albeit rather limited, that is actually limited to a few hundred - produce the number of copies. In order to improve the ink transfer onto the die in the typewriter labeling a hard film was placed ( for example of plastic ) between these and the roller in the rule.

Applications

The relatively inexpensive hectograph (also Umdrucker or colloquially pasta machines ) made ​​it possible, for example, pupils and students to produce leaflets and newspapers without having to use the services of a printing company in claim (1970 cost simple, easily transportable devices about 130 DM). In the office, in schools and teaching the process played an important role, as it was the cheapest by far way to produce copies. In West Germany hectograph schools were until the early 90s widespread until they were increasingly replaced by the now affordable for schools has become a low budget photocopiers.

For people in the political resistance Hektographie in the late 19th and early 20th century was often the only way to print results in significant number to spread.

Hektographien however, are characterized (by no means comparable to the xerography or today's inkjet or laser printing ) characterized by a markedly inferior print image that also often not pure black, but as with an ink pen was purple and that was getting worse by blurring with increasing support. To mitigate this effect, it was a special coated Hektographiepapier. In addition, usual Hektographien out easily. Graphics were not possible due to lack of opportunity for screening purposes only line drawings. The matrices were generally used only once; Error could be corrected only with special paint correction. In addition, fresh Hektographien adhered to a characteristic odor of ethanol.

Related methods and apparatuses

Similar devices are invented by Edison mimeograph, as well as autograph, Chromograph, multigraph kilo graph Ormig ( DDR synonym for Hektographie, also occurring in the West, according to the (West) Berlin Ormig organization means GmbH), copy press etc.

Compared with the copies made with highly perishable aniline inks denotes the Kollographie Jacobsen real progress. According to this method one writes with a special Kamp ash ink on good bond paper transfers the writing on a moistened glue board and blackens them with the help of a roll with printer 's ink. The latter remains liable only to the area covered by the scriptures of the glue board if they had first been moistened enough. The copy will also get here by simply placing the paper and the exercise of a moderate pressure. For each new copy of the writing on the glue board must again be blackened, and so you can get to 150 pure Umdrucke of which have the same last blackness as the first, while the hectographic copies turn out last weaker.

In Zuccatos Trypograph is a kind of screen-printing process. This one writes with a hard pen on a specially -prepared paper, which is placed on a finely roughened iron board. By printing the paper gets to the deformed through the scriptures smallest holes and is as it were transformed into a template. This is now fixed in an apparatus with printing frame, but underneath it pushes you every time the sheet to be printed ordinary paper. Then it travels over the stencil with a rag soaked with some color squeegee, the ink penetrates through the holes formed on the paper and a copy of the font. A single template should be able to deliver up to 7000 impressions, but encourage the production so fast that you can produce 400 prints in an hour.

With a similar procedure, but fully automated as a copy machine work called Risographie devices. The classic blueprint was produced by the diazo process.

Another method for the production of printing matrixes uses a thermal printing process, this special die sets ( color and stencil sheet ) are offered. This made ​​it possible to produce from one-sided originals printed in black using a Thermo- copying process any number of equal pressure dies. To this end the one-sided black printed original was drawn by the thermal copier in contact. This consists of a glass -driven roller, which is heated by a halogen bar from the inside. Rubber rollers guide the original together with the die on this roll, with the black font heated so much that the ink layer of the ink sheet melts and the ink is transferred to the matrix. However, the white portions of the original remain below the melting temperature of the ink layer. The backing paper of the thermal copy matrices is much thinner, by which both the printing quality and the size of pad suffers. Such matrices are still used today by many tattoo parlors to transfer drawings onto the skin.