When printing the sample printing operation in the process of the most common method used to check the printing quality. Both monochrome printing and color printing, the operator must often use his eyes to print compared with sample again and again, to find out the difference between sample and printing quality, timely correction, to ensure the quality of printing products. When printing the sample the following several problems worth our attention:
One, the strength of the light color to print proof directly affect the judgment
The strength of the light not only have influence on the light and shade of color, also will change the color of the face.
We observed a cylinder by light at ordinary times, face side of light tones, backlit face is dark color. The junction is divided into light and shade is middle.
The same object, under the standard light source is a positive color, if the light gradually stronger, its are tonal also subsequently XiangMingLiang hue shift, light enhancement to a certain extent, can be any color into white. Black porcelain its glitter also is white, because of the focused light spot, and strongly reflected. Similarly, the light is gradually reduced, various color XiangMingDu low hue shift, light decreases to a certain extent, any color will be black, because is black objects do not reflect any light. Table 1 is the strength of the light effect on the color.
Printing workshop see sample must conform to the requirements, the general requirements of illuminance reached around 100 lx, can correctly identify the color.
2, color sample with light look under the sample is difference
In actual production, mostly work in under the irradiation of power supply, and each light source is a certain color. This will give correct judgment manuscript or product color bring certain difficulties, under the light color, the color change is generally the same color becomes shallow, complementary color darker, such as: red light color, light red, yellow orange,
Dark green, green dark, white and red.
Green color, shallow green, green becomes shallow, yellow green yellow, red, black, white, green.
Under the yellow light color, light yellow, magenta red, blue, green, blue, black, white and yellow.
Under the blue color, shallow blue, light blue, dark green, yellow, black, white and blue.
In the printing workshop, generally choose higher color temperature (3500 ~ 4100 k), color factor good fluorescent lamp as the light source, but must pay attention to the fluorescent lamp slightly purple.