Grey balance in the hottest printing

On the gray balance in printing

the printing process (mainly refers to offset printing) is to decompose the hue of the continuous tone original, and make the four monochrome eye tone plates of yellow, magenta, cyan and black respectively, and then overprint each eye tone monochrome plate to realize color restoration. Due to the ever-changing colors on printed matter, it is impossible to choose experimental schemes for different levels of each color; Measuring the size of the sample for inspection and control, so people have explored the use of testing the neutral gray balance method to control the reduction of printing color. Usually, under a certain printing suitability, the dot ladder of yellow, magenta and cyan plates is used to combine overprint according to a certain dot proportion from light to deep. The color of the ladder after overprint loses hue and saturation, but only gray with different lightness. This process is called gray balance of printing. Because gray has neither hue nor saturation in the three color attributes, it belongs to neutral color (also known as "achromatic"), so it is sometimes called neutral gray balance

the function of gray balance is to indirectly control all tones on the whole picture by controlling the gray part of the picture. It is a yardstick to measure whether the color separation and plate making and the color set are correct. It is the principle that all processes in the whole process of reproduction should be observed and implemented together for data-based and standardized production

first, the principle of gray balance

theoretically, if two colors are complementary to each other, then the two colors will become neutral after mixing in an appropriate proportion, which indicates that when two colors are complementary to each other, their mixing also has a problem of balance. Otherwise, Suning yunshang will show neutral gray on the daily limit board for 5 times. However, it is not the balance of the three primary colors, but the quantitative balance of the two complementary colors. In fact, the transformation of two complementary colors into neutral gray after appropriate mixing is the basis of all gray balance. The gray balance of the three primary colors is also the method of color synthesis. Finally, they are summed up as the balance of complementary colors. We mix any two primary colors in the three primary colors of printing yellow, magenta and cyan, and the resulting intermediate color is always complementary to the third primary color:

Yellow + magenta = red, which is a pair of complementary colors with cyan

magenta + technical conditions for high strength large hexagon head bolts, large hexagon nuts and gaskets for steel structures gb/t1228 ~ 1231-91 green = blue purple, which is a pair of complementary colors with yellow

green + yellow = green, and magenta are a pair of complementary colors

therefore, the principle of gray balance of printing three primary colors is a specific manifestation of the complementary color law

second, the necessary conditions to achieve gray balance

it is conditional to achieve gray balance. Each color of yellow, magenta and cyan inks involved in the balance has a certain color and saturation, which are the necessary conditions to determine whether the synthetic color is balanced

1. The influence of color relative balance. Neutral gray balance can not be obtained after any of several different hues are mixed. Take red, orange and yellow for example. No matter how you mix them, you can't reach neutral gray. This is because among the three colors, orange is not an independent color. It can be obtained by mixing red and yellow. Red and yellow are not complementary colors, and it is impossible to produce neutral gray. Obviously, the hues of the colors involved in the mixing, or they are complementary colors, or they can produce complementary colors after mixing. Only in this way, the mixing of hues can produce gray balance. The hue of the printing three primary colors meets this condition. However, in the three primary colors of yellow, magenta and cyan, any hue shift in printing will affect the original balance. The hue shift is the color shift, which is an important factor to determine the balance of the three primary colors

2. The influence of saturation on the balance, the amount of each color participating in the gray balance should be appropriate. This requires participation in balancing the amount of color used in the research and development of experimental machines, neither more nor less. Even two complementary colors must be mixed in equal amounts to balance. If the two colors are not equal, the hue of the mixing result must shift to the hue with more colors. In printing, the saturation of color is expressed by density or the area ratio of dots

source: liuningjun, Jiangsu publishing school