Discussion on ink color selection and deployment specification

The color of packaging and decorating prints requires a strong physical sense. Therefore, the selection and deployment of ink colors is very important. In theory, no matter how colorful the ink color is, it should guide the machine printing with the color when the cans are opened. However, in the actual printing, the color of the ink when opening the can often does not meet the requirements of the color of the draft, and due to various factors such as the process method, environmental conditions, and substrate materials, the printability of the ink when opening the can is sometimes also not ideal. Therefore, when printing, it is often necessary to adjust the ink fluidity, drying property and viscousness with various ink additives according to different situations. Such as: add varnish, dry oil, dilute agent, remover and so on. The following combination of work experience, talk about a few issues related to ink deployment.

First, ink color matching

Ink transfer workers must understand the basic specifications of color matching, as well as the type of ink and the performance of the ink itself. Otherwise, the color of the mixed ink may not reach the customer's requested color sample effect. In color matching, the ink color should be formulated according to the actual printing process, ink layer thickness, printing material and other conditions. When choosing the ink color, consider the gloss, hue, tinting strength and hiding power of the ink. In addition, in order to adapt to the needs of the printed products, when the color inks are prepared with the primary color inks or the spot color inks are prepared, appropriate processing is performed to obtain the suitability for printing.

In a specific color palette, first of all, the composite ratio of the main color and the auxiliary color should be identified. The mixing of different proportions of the primary color ink can be used to formulate different ink color rendering effects. The synthesis ratio can be referred to Table 1.

Table 1 Ink Mixing Ratio Table Primary Color Synthetic Ratio Coloring Condition Magenta (Peachish) Yellow (Medium Yellow) Blue (Combo Blue) 250 751 : 0 : 3 Dark Blue Purple 750 253 : 0 : Ching Lin 500501 : 0 : 1 Purple 025 750 : 1 : 3 dark green 080200 : 4 : 1 apple green 075250 : 3 : 1 green 050500 : 1 : green 257501 : 3 : 0 deep yellow 5050 : 1 : 0 red 752503 : 1 : 0 orange red 5025252 : 1:1 red purple 10025254 1:1:1 brown brown 2525501:1:2 olive 2550251:2:1 bronze 25100251:4:1 false gold 25251001:1:4 dark green 5050501:1:1 black

The distribution ratio of light ink is as follows:
Pale red ink: mainly 8011 or 8015 lighter, slightly increase red, orange;
Five-color ink: mainly 8011 or 8015 lighter, slightly orange, yellow;
Gray ink: mainly 8011 or 8015 lighter, slightly black ink;
Light blue ink: mainly 8011 or 8015 lighter, slightly silver, black ink;
Lake Green Ink: mainly 8011 or 8015 lighter, slightly add Kong Lan and Zhong Huang;
The preparation of the ink should be carried out from light to dark, and the pale ink (dissolving agent) cannot be mixed on the basis of the dark ink. The color of dark-to-light deployment ink is not easy to grasp, and it is easy to cause excessive ink consumption and even rework. The dark ink should be gradually added based on the pale ink (disposal agent), and the color samples should be tested repeatedly until the color meets the requirements of the original. With a good ink sample, you can get the mixing ratio of the main color of the ink and the auxiliary color, and then determine the production requirement of the ink according to the layout, paper, number of prints and process requirements of the print.

The color of the ink is blended with the primary or inter-color ink, which can be corrected with its complementary color. For example, when the tuned ink is too purple, it can be corrected by adding red color; when the blue taste is too heavy, orange ink can be used to correct. In addition, prints that require quick drying can be diluted with 8019 lightening agent to achieve a fast drying effect.

Second, the ink printability adjustment

General properties of offset resin inks are shown in Table 2.
Table 2 Ink Characteristics Table Technical Items Item Flow (mm/25°C) Viscosity (32°C) Coated Paper Bonding Speed ​​Minute/Standard Condition Conjunctiva Dryness (hours)
Standard Conditions Black Crimson Red Yellow 31~35
30～34
31~35
29～3310～12
10 to 12
10 to 12
<20
<20
<20
<206 to 10
6 to 10
6 to 10
6 to 10

(1) Adjustment of ink thickness

The fluidity, thixotropy, and other properties of the ink used in the production must be compatible with the printability. The original ink is thicker and sticky, and it is usually not suitable for direct printing on the machine. Because the viscosity of the ink is too large, the ink in the ink fountain is not easily transmitted to the ink roller, and the ink on the ink roller is not easily rotated evenly, which directly affects the printing quality. Moreover, the viscosity of the ink is too large, and problems such as roll-up, paper-feeding, and stick-out are easily generated. Intensity adjustment of ink should pay attention to the following points:

(1) The printing ink with a smaller printing area and the reverse printing on the field layout should be thicker;
2 The surface of the printing paper is smooth and strong, and the ink should be thicker;
3 printing stacks of color printing (second color), the ink should be thicker;
5 The printing shop has a high temperature and the ink should be thicker.

(2) Adjustment of ink dryness

Dryness of ink is mainly affected by the following factors, and should be adjusted according to specific conditions.
1 The size of the printing surface, the thickness of the ink layer, the printed matter with a small print face and a thin ink layer are faster than the printed matter with a large print face and a thick ink layer;
2 Due to the nature of paper, the ink on the soft or alkaline paper of the fiber dries faster than the ink on the paper that is tight or smooth on the fiber;
3. Affected by the temperature of the workshop, the ink in the workshop with high temperature, low relative humidity and good ventilation conditions is drying faster than the workshop with low temperature, high relative humidity and poor ventilation conditions.

(3) Production of ink The actual production shows that the amount of formulated ink must be slightly larger than the amount of ink used for production. Generally, after the production task is completed, the amount of ink remaining should not exceed 5-10% of the total amount of ink to be allocated. . The main factors that affect the consumption of ink are:
1 The size of the printed imagery area;
2 The strength of the ink absorption performance of the printing paper, the hiding power of the actual ink layer;
3 how much of the print;
5 monochrome printing or multicolor printing;
5 ink coloring power and ink density.
Should first determine the unit of ink consumption of the print, that is, the consumption of ink per thousand prints, and then find the ink consumption of the entire print, multiplied by a factor of insurance, that is, the production of ink. (See Table 3)
Table 3 Ink relative dosage meter Variety of dosage Printing surface Non-coated paper (printing times) Coated paper (printing times) Light color ink 1 kg 16 open (Full version of ink ground) 1000-12002000-2500 Dark ink 1 kg 16 open (full version of ink 1500-20003500-4000

Note: Non-coated paper prints are printed twice less than the coated paper.
The above is an analysis of the adjustment of printing ink color and printing ink suitability based on the actual production amount and various factors during printing. (Du Debao)

Reprinted from: Fine Art Network