DE132736C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The emergence of new color nuances is based on the printing of several color forms together partly on optical mixture, partly on pigment mixture.

The optical mixture arises from the fact that two are placed next to each other on the paper Color dots or dashes, as shown in the lithographic grain manner, line drawing or in the autotypical halftone dot is to make a common color impression on the eye, i.e. by adding the color impressions on both sides.

While the optical mixture only takes place in our eyes, the so-called Pigment mixture through the pigments or color bodies themselves. Condition for the formation of the pigment mixture is the transparency of the color bodies. White light must have two transparent ones superimposed on one another Layers of paint, such as this e.g. B. glaze colors happen to appear colored to our eyes.

Pigment mixture is the green we see when we go through a yellow and one blue glass looking at a white surface.

The process here is comparable to a subtraction in that only the two Glasses collectively penetrate green light rays into our eyes.

The same pigment mixture arises when one prints two colors on glaze weifses paper, only a double absorption takes place here, 'even on the ^WT ege of light through the layers of paint on paper and then on the way back to the eye.

The condition for the formation of such pigment mixtures in color printing is that two or more color forms have common printing areas at the respective point.

In this pigment mixture, which is necessary for the creation of new color nuances, respectively. In the required common printing areas of several color forms, the main reason is to seek why the different colors in immediate succession when wet cannot be printed on top of one another in any number of copies.

This is explained in more detail below:

Should z. B. In a fashion picture, a dress whose drawing is already given by the black plate is given a purple color, So it would be obvious if another dress already had one on the same fashion picture would have red color and another a blue one, for this violet dress no separate printing form to produce, but the desired color by overprinting Roth and To achieve blue and for this purpose this dress in the red and blue form to give common printing areas.

The developing process is now as follows:

If the red color is printed first, the paper comes after the red Has left the printing form, as a result of the continued

Printing area

movement of the machine to the blue printing form, and a violet mixed color will result from the imprint of the blue on the red that has already been printed. _:

At the same time, however, the red color is also transferred from the paper to the solid blue printing form be transferred, since of course "between two very wet colors, indifferent, whether they are on paper or on a printing form, a certain amount of compensation takes place.

This on the blue
Roth clapped himself on the next pass of the blue printing forme under the corresponding blue inking unit. As a result of the frequent repetition of the same process in the course of the printing of the edition, the blue applicator roller and the blue inking system in general will gradually acquire a violet color, i.e. a mixture with red, the intensity of which is proportional to the size of the common printing areas blue and red printing form and the amount of the edition. .

Because of this change in the blue inking to violet, there will perhaps be no great disadvantage for the coloring of the said violet dress, but there will be for all those places which are supposed to print in pure blue. In addition, a lush green dress may be desired on the fashion picture in question, for which, for economic reasons, a separate green printing form should not be produced, but which should be created by overprinting a common printing area of the yellow and blue printing form, and it is immediately apparent that from a yellow and a violet-blue no such juicy green mixture can be obtained as from a yellow and a pure blue., · ■ · ■ .., -. _:

The mixing of the inking units with the color of the preceding inking unit, which, as just described, by transferring parts of it to the surface of the paper printed previous color on the own printing forme is created, sets the amount of the edition very low limits.

This inconvenience can now be avoided by using the second and the second following printing forms after they have given their color to the surface to be printed that have been printed or clipped back onto the printing form from this surface Ink quantities of previous inking units are removed, namely before these printing forms be re-colored by the respective inking units belonging to them.

This removal is expedient mechanically by means of lift-off rollers and the like take place, like those in printing technology already in many cases for other purposes available.

Claims (1)

Patent claim:
Process for enabling the immediate printing together of two and more colors in any number of copies, characterized in that the mixed colors which damage the saturation and luminosity of the colors are removed from the second and further printing forms after the printing has taken place, before the printing forms are returned to the area of the inking units reach.