Several requirements to pay attention to when look

Several requirements to pay attention to when looking at samples (I)

I: the intensity of light directly affects the judgment of the color of printed samples. The intensity of light not only affects the brightness of the color, but also changes the appearance of the color

at ordinary times, we observe a light receiving cylinder. The light facing side is bright, and the backlight side is dark. Why does the tensile testing machine prompt online failure during startup test? The online failure shows that the tension machine software can not be successfully connected with the machine. The combination of light and dark is the middle tone. The same object is positive color under the standard light source. If the light gradually becomes stronger, its hue will also change to a bright hue. When the light is enhanced to a certain extent, any color can turn white. The reflective point of black porcelain is also white, because the light at the reflective point is concentrated and strongly reflected. Similarly, the light gradually decreases, and various colors change to the hue with low lightness. When the light weakens to a certain extent, any color will turn black, because the object does not reflect any light is black. Table 1 shows the influence of light intensity on color

the sample viewing platform in the printing workshop must meet the requirements. Generally, the illumination is required to be about 100lx in order to correctly identify the color

II: there are differences between sample viewing under colored light and that under sunlight. In production practice, most of them work under the irradiation of power supply, and each light source has a certain color. This makes it difficult to correctly judge the color of the original or product. When viewing the color under color light, the color change is generally the same color becomes lighter, and the complementary color becomes darker. For example, when viewing the color under red light, the red becomes lighter, the Yellow becomes orange, and the green becomes timely protected; Dark, blue turns dark, white turns red

when viewing color under green light, green becomes lighter, green becomes lighter, yellow becomes green yellow, red becomes black, white becomes green

when looking at the color under yellow light, yellow turns light, magenta turns red, blue turns green, blue turns black, and white turns yellow

when viewing color under blue light, blue becomes lighter, blue becomes lighter, green becomes darker, yellow becomes black, and white becomes blue

in the printing workshop, fluorescent lamps with high color temperature (3500~4100k) and good color rendering coefficient are generally selected as the sample viewing light source, but it should be noted that the fluorescent lamps are slightly blue and purple

III: the results will be slightly different if you look at the sample first and then the print and then the sample, and you will feel different when you look at one color twice. This phenomenon is called sequential color contrast reaction, and the changes are shown in Table 2

why is there a sequential color contrast reaction? This is because the color you look at first excites the color nerve fibers of that color, and then look at other colors immediately. Other color nerves are soon excited and cause color sensation, while the color nerves that look at color first are in a state of inhibition after excitation, and then apply preservatives with low viscosity, causing negative color reaction. This reaction, coupled with the hue of the new look color, forms a new color, so it changes the look color. Moreover, the hue of the change is still regular. It is to look at the complementary color of the color first. The change is a field of pollution prevention and control with scope and economic value

to understand the above three aspects and their change rules, we should pay attention to them when we actually look at the samples, so as to ensure the stability and improvement of the quality of printing products

the change trend of the color that the eye looks at first and then looks at again

red, yellow, green, blue, purple and white

lateritic, red and green flavor, yellow, fresh green, cyan, cyan, cyan, cyan, blue, purple and purple

green, fresh red orange, grey, green, purple, magenta

blue orange, golden yellow, green, grey, blue, red, light orange

purple orange, lemon yellow, green, cyan, blue, grey, purple and green

printing is divided into monochrome printing Color printing. Monochrome printing is a printing method limited to one color. Color printing can print full-color pictures. Color printing mostly adopts color separation plates to reflect various hues. Color separation plates are mostly composed of red (m), yellow (y), blue (c) and black (k) four-color line plates. According to the color separation principle, the hue of the color draft of the color separation plate can be directly marked with words with the dot fraction of CMYK in the chromatography. When special colors are needed, special colors other than these four colors must be used to set the spot color version. The color identification of the spot color version can specify a certain hue in the chromatography for special debugging

printing is divided into monochrome printing and color printing. Monochrome printing is a printing method limited to one color. Color printing can print full-color pictures. Color printing mostly adopts color separation plates to reflect various hues. Color separation plates are mostly composed of red (m), yellow (y), blue (c) and black (k) four-color line plates. According to the color separation principle, the hue of the color draft of the color separation plate can be directly marked with words with the dot fraction of CMYK in the chromatography. When special colors are needed, special colors other than these four colors must be used to set the spot color version. The color identification of the spot color version can specify a certain hue in the chromatography for special debugging