SU1623876A1 - Test object for four-color offset printing - Google Patents

Abstract

The invention relates to printing, in particular to test objects for four-color offset printing, used for the process of making color-separated raster transparencies and for determining the replacement of three color inks for black. The purpose of the invention is to improve the accuracy of the evaluation of reproduction of color originals. The test object contains blocks of triad and black color overlay fields, where each field is made by overlaying two color inks: yellow + purple, yellow + blue and blue + purple with a combination of values, relative areas of raster elements from 0 to 100%, each field The block contains at least two stages of the third color paint and a constant amount of black paint with discrete variation of the relative areas of the raster elements from 0 to 100% for each block. 1 ill., 1 tab. (/ WITH

Description

The invention relates to the printing industry, in particular to test objects for four-color offset printing, used for the process of making frosted images and determining the replacement of the triad color inks with black ink.

The purpose of the invention is to improve the accuracy of the evaluation of the reproduction of color originals.

The drawing shows one block of the test object, for example, a binary yellow + purpurna. In the drawing, the following notation is accepted: F - yellow, P - purpurna, D - blue, H - black of the triad paint; K - red biar, i.e. F + P; 3 - green binary, i.e.

G + F; F is a purple binary, i.e. Г + П (indices correspond to the values of the relative area of raster elements on transparencies).

The test object may consist, for example, of 39 blocks. It is designed in such a way that colors close in color tone are concentrated as close as possible to each other in tone, which facilitates color selection and color comparison. Two-color binar colors can be taken as a basis, to which a limited amount is added (up to S e 30 %) of the third color paint: red (К) from Ж and П with additional Г; green (3) from F and T with

O N O- X

additional P; violet-blue (F) ie P and D with additional F;

The step width for monochromatic colors and pure biiera, for example, 10 mm, for three-color (with additional color paint) - for example, 7 mm. Each block of the test object can be performed, for example, 8 levels of black paint with S 0, 10, 20, 35, 50, 65, 80, 9 5%.

The structure of the test object is described in the table.

The indicated size ranges of raster points include the following steps (S,%):

OZO: 0, 5, 10, 20, 30 (5 steps) 40-95: 40, 50, 65, 80, 95 (5 sta

penalties) 0-95 O, 5, 10, 20, 30, 40, 50,

65, 80, 95 (10 steps) The test object works as follows.

The image of the test object is printed using the technology, materials, and equipment of the enterprise where the test object is used. The image of the test object on the print, for example, determines:

1. The color tone, which will be obtained by this technology on specific materials and equipment, if

on the color separations of the reproduced original transparencies, the size of the raster elements, for example, is as follows: F jo Ilio Ho z K is yellow 30%, purpurn 30%, blue 30% and black 30%. On the test object, a block of fields for the Cs На is found and in the block, the field with ZheldPzo is determined. For this floor, one of the steps created by the third colored paint G} 0 is the desired color, which is defined in the test object as

G} 0 Peog3o to W2. The magnitudes of the relative area of the raster elements on the color separations of the reproduced image of the original, when the color cast of the individual artistically important image elements is set by art

Q

five

0

five

about

P

Q

five

com or publisher. This is carried out as follows. Visually, the comparison method is used to find the floor of the test object according to the color tone corresponding to that required in the order. The magnitude of the raster elements for four printing inks is determined from the test object. The magnitude of the raster elements (in%) are the desired and necessary to obtain the desired color on this paper using the same printing inks and technology.

Using the proposed technical solution allows you to quickly monitor and adjust electronic color correctors, monitor and evaluate finished raster color separations, determine the type of proofreading and retouching, adjust the parameters of the printing process, and also provide planning and selection of the percentage of raster elements required to reproduce individual colors. reproducible l printing print process of the original.

Claims (1)

Invention Formula A test object for four-color offset printing containing blocks of triad and black color overlay fields, where each field is made by overlaying two color inks: yellow + purple, yellow + blue and blue + purple with a combination of discrete values of the relative areas of the raster elements from 0 to 100 %, with the addition of a constant amount of the third color paint and black for each block with the creation of a tonal step in each field, characterized in that, in order to improve the accuracy of the reproduction of color originals c, each field of the block contains at least two stages of the third color paint and a constant amount of black paint with discrete variation of the magnitude - relative areas of the raster elements from 0 to 100% for each block.