Main factors affecting gray balance in the most po

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The main factor affecting the gray balance in flexographic printing

insoluble in water and lye in printing reproduction, gray balance is used to determine whether the printing color is balanced or biased, which runs through the whole process of printing reproduction. In color flexographic printing, it is also a problem that should be paid special attention to

I. concept and function of grey balance

1 The basic concept of gray balance

according to the subtractive color rendering theory, the superposition of the maximum saturation of the three primary colors of ink should appear black. However, the hue, lightness and saturation of the ink used in actual production have different degrees of deviation. The whiteness, smoothness and absorption of the paper will also cause the color density value to be not disordered. The three primary color inks are superimposed in equal quantities, which is reflected on the paper. Neutral gray cannot be obtained, but slightly tawny gray

because the colors on the printed matter are ever-changing, people have explored the method of repairing the gray balance to control the reducibility of the printing color. Under a certain printability, use the dot ladder of yellow, magenta and cyan printing ink to combine overprint according to a certain dot ratio from shallow to deep, and obtain the gray balance. At this time, the dot percentage of yellow, magenta and cyan of the ladder is the gray balance data of this point. Because gray has neither hue nor saturation in the three color attributes, it is a neutral color, so sometimes it is also called neutral gray

the most commonly used method to determine the gray balance is to print a gray scale, that is, to print four-color ink color codes of yellow, blue and black next to the printed matter, so as to control and adjust the gradation and color of the color image. In order to achieve the perfect reproduction of color, it is necessary to change the dot area ratio of the three primary colors ink according to the actual characteristics of the ink during printing, so that the three primary colors ink will show an accurate gray balance after overprint

2. The role of controlling grey balance

grey balance is one of the most important contents in the theory of printing reproduction. Controlling gray balance is to indirectly control all tones on the whole picture by controlling the gray Department of the picture. It is a standard to measure the accuracy of color separation plate making and color printing. It is a means to determine whether the printing color is biased and whether it is faithful to the original. It is also the hub of digital and scientific management of the printing process

in printing reproduction, gray balance is used to determine whether the printing color is balanced or biased, which runs through the whole process of printing reproduction. In color flexographic printing, it is also a problem that should be paid special attention to

II. Factors affecting the gray balance in flexography

a set of printing gray balance data is for a certain ink, paper and ink layer thickness. There are many factors that affect the gray balance in printing, including printing technology, materials and equipment. The main influencing factors are:

1 Influence of ink color quality

any slight change of primary color ink in printing will lead to color deviation. Different inks have different densities of C, m, y and B. There are four parameters that characterize the characteristics of inks, namely, ink color intensity, hue error, gray scale and color efficiency

ink color intensity determines the saturation of ink color, and also affects the correctness of the hue of intermediate and composite colors of overprint and whether neutral gray can be balanced. Hue error, also known as color deviation. The color of the ink is impure, which leads to poor spectral absorption, undue density and hue error

the gray scale of an ink refers to the achromatic components contained in an ink. It has a great influence on the saturation of ink. The smaller the percentage of gray, the higher the saturation of ink

ink color efficiency refers to that an ink should absorb one-third of the color light and reflect two-thirds of the color light. The ink has improper absorption or insufficient absorption, which will reduce the color efficiency of the ink

before selecting different inks for printing, it is necessary to measure the basic characteristics of the ink and the physical and chemical characteristics of the ink, and establish a gray balance relationship suitable for this kind of ink, so that these factors can be considered when formulating the printing process and plate making. In addition, the printability of ink also affects the gray balance. For example, the changes of ink viscosity, rheology and ink layer thickness will affect the color reproduction of the original, leading to the destruction of the gray balance

it should be exaggerated here. In the process of pre press color separation and plate making, because more than 20 kinds of ink data provided in Photoshop are for offset printing, there is no unique ink parameters for flexographic printing. If the flexographic printing is still made with the parameters of offset printing, it is inevitable that the gray balance will be out of control, so it is necessary to pass the sample test according to the ink used by the printing enterprise in detail, and according to the characteristics of flexographic printing, For example, a set of flexo printing parameters are established, taking into account the color balance of flexo printing from the color separation

2. The influence of the characteristics of printing materials on the gray balance

the gray balance data is affected by the materials used in printing. Taking paper as an example, different types of paper also have great differences in the color rendering ability of the same ink, and coated paper is better than glue rdquo; According to Liu Jianbo, chairman of Anda technology, the coated paper reflects a very rich level of tone, and the offset paper is lighter. Even the coated paper of 157g/cm2 has a certain difference in the impact on the gray balance because of the different origin. The whiteness, smoothness, absorbency, gloss, opacity and pH of paper will also affect the ash balance

therefore, in the process of flexo plate making and printing, it is necessary to consider that different papers have different gray balance data, and the precision of points and the size of gradient contrast should be adjusted appropriately. The company has set up Yongxing new energy integration in Yifeng County, Jiangxi Province

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