Introduction: Printing is widely used in life, no matter what most places will use printing. In the printing process, many factors affecting the printing effect, so the printing will first print samples and samples for comparison, in case there are errors in time to correct, to ensure the perfection of the print, share the printing to see the sample to pay attention to a few requirements, the content for friends to refer to.
Printing to see the sample is the most common method used in the printing operation to check and control the quality of printing, whether monochrome printing or color printing, printing process, the operator must often use their eyes will be repeatedly compared with the sample to find out the difference between the print and the sample, timely correction to ensure the quality of printed products.
The intensity of light
The intensity of light directly affects the judgment of the color of the print sample, the intensity of light not only has an impact on the color of light and dark, but also change the color appearance.
Usually we observe a lighted column, the light side for the light tone, the backlight side for the dark tone. The combination of light and dark part is the middle tone.
The same object, in the standard light source is positive color, if the light gradually becomes stronger, its hue also changed to the bright hue, light enhanced to a certain extent, any color can be changed to white. Black porcelain its reflective point is also white, because the reflective point at the light concentration, and strongly reflected.
Similarly, the light gradually reduced, a variety of colors to the lightness of the low hue shift, light diminished to a certain extent, any color will become black, because the object does not reflect any light is black.
Printing workshop viewing table must meet the requirements of the general requirements of illumination to about 100lx, in order to correctly identify the color.
Different color light
Color light to look at the sample and daylight under the sample is different, in production practice, most are working under the irradiation of power, and each light source with a certain color.
This brings certain difficulties to correctly judge the original or product color, color light under the color viewing, color change is generally the same color becomes lighter, complementary color becomes darker.
Red light color, red becomes lighter, yellow becomes orange, green becomes dark, green becomes dark, white becomes red.
Green light color, green becomes light, green becomes light, yellow becomes green yellow, red becomes black, white becomes green.
Under yellow light, yellow becomes lighter, magenta becomes red, green becomes green, blue becomes black, white becomes yellow.
Blue light viewing, blue becomes light, green becomes light, green becomes dark, yellow becomes black, white becomes blue.
In the printing workshop, generally choose a higher color temperature (3500 ~ 4100k), the color rendering coefficient of the better daylight as a sample light source, but note that the daylight is slightly blue-violet.
First and then color contrast
First look at the sample and then look at the print and first look at the print and then look at the sample, the results will be slightly different, divided into two look at a color when the feeling is not the same.
This phenomenon is called the successive color contrast reaction.
Why is there a sequential color contrast reaction? This is because the first color to look at the color nerve fibers of the color excitation, and immediately look at other colors, other color nerves quickly excited to cause color sensation, while the first color nerve in the state of inhibition after excitation, and then slow excitation, causing a negative color phase response.
This reaction, together with the hue of the new color, forms a new color, so it changes the color after looking. And change the hue or a regular pattern, is to first look at the color of the complementary aspects of the color change.
Understand the above three aspects and master their laws of change, we should pay attention to when actually looking at the sample, so as to ensure the stability and improve the quality of printed products.
The eye first look at the color, then look at the color of the change tendency
red yellow green blue purple white
red earth red green flavor yellow bright green green blue light green
yellow violet-flavored red gray-yellow lime green bright blue blue violet slight violet
green bright red orange gray green purple red violet magenta
Blue Orange Golden Yellow Green Gray Blue Red Violet Light Orange
purple orange lemon yellow yellow green green blue gray violet green yellow
The print is divided into monochrome printing and color printing. Monochrome printing is a printing method that is limited to one color. Color printing, on the other hand, allows the printing of full-color images. Most color printing uses color separation plates to reflect the various hues, color separation plates are mostly composed of red (M), yellow (Y), blue (C) and black (K) four-color screen plate.
Color separation version of the color can be based on the color separation principle, directly marked with text in the chromatography of the CMYK network into the number. In the need for special colors, it is necessary to use the four colors outside the special color, set the spot color version. Special color version of the color logo can be specified in the chromatography of a particular color phase, specifically debugged.
Printing color representation
Ink printing color, there are generally two methods.
① printing color using four-color ink, mixed dot and overlap printing.
② mixed printing ink, modulation of the spot color, that is, the use of spot color printing, with solid color or dot representation of color. These two methods of color designation and plate making methods are different in print design.
Grayscale for monochrome printing
In monochrome printing, the darkest solid base is 100%; white is 0%, and the different shades of gray in between are made by calling different dots, i.e., using percentage control. In order to facilitate reading, usually in 50% to 100% of the dark gray tones on the application of anti-white letters, and between 50% and 0% with black letters, but should also be considered according to the different monochrome and discretion.
Color printing of four-color labeling
Color printing is printed in red, yellow, blue, black four-color printing to produce a thousand different colors. It can use color separation plate printing colors. However, the color of the text or graphics desired in the design can use the color scale to consult the CMYK value of each color. But some special colors such as gold, silver and fluorescent colors can not be composed of four-color ink overlay, must be printed with spot-color ink of the spot-color plate.
Color plate changes
Modern design needs are diverse and varied, to express a more perfect mood, or more special effects, only restore some of the original image color, and can not achieve the required requirements. Therefore, the color plate process can be used to change or convert the order and number of color plates to achieve special color design requirements.
Black and white positive to dichroic
The use of two sets of color plates, using a single-color press twice to complete the printing, or change the color press once to complete. Using two-color printing usually uses a single-color black plate, and then ingests another color as the color tone of the color plate combined printing. In the case of the original is not very good, this method of two-color printing, often producing unexpected results.
Color plate replacement printing
Color plate replacement printing is in the printing design, the color plate of a certain color swap, resulting in a change of color plate. The purpose is to pursue a special picture effect, which can often bring unexpected results. In the color separation of the four plates, if two or three of the colors will be exchanged for printing, will change the entire original layout of the tone, resulting in great changes.
For example: the green tree consists of yellow, blue and a little black; if the yellow version to red printing, while the blue version remains unchanged, the green tree will become purple, a similar practice in some poster design and layout occasionally used, will get a novel effect.
Positive to two-color is in the four versions of two of the plates will be taken away, only two versions of printing, that is, two-color printing. A third color can be produced, such as blue mixed with yellow to get green, as to get the shade of green is completely dependent on the ratio of blue to yellow dots produced. A normal tone made out of color pictures, through a certain two color plate to print to achieve a special color effect.
Occasionally, this type of printing is used in design to create a fresh feeling. It can be used to create a special creative effect when applied to the environment, atmosphere, time and season of a scene.
To seek special tonal effects, one of the four-color plates can be removed and the three-color plate retained. In order to make the picture effect clear and prominent, often three colors in the heavier, darker tone of the version as the main color.
You can also use one of the three plates as a spot color printing, for example, the black plate made of silver or gold will produce a special color combination. The use of color plate change techniques, suitable for exaggeration, emphasis and special effects of processing.
Monochrome printing refers to the use of one plate, which can be black, color plate printing, or spot color printing. Spot color printing refers to the special modulation of a special color required in the design as a base color, through a printing plate to complete.
Monochrome printing is more widely used and produces the same rich tones to achieve satisfactory results. In monochrome printing, color paper can also be used as the base color, printing a result similar to dichroic printing, but with a special flavor. Special colors Special colors include glossy color printing and fluorescent color printing.
Glossy color printing mainly refers to the printing of gold or printing silver, to make a spot-color version, generally using gold ink or silver ink printing, or gold powder, silver powder and bright oil, quick-drying agent, such as the deployment of printing.
Usually the best way to print gold and silver to lay the base color, this is because the gold or silver ink printed directly on the surface of the paper, because the degree of oil absorption on the paper surface will affect the luster of gold and silver ink . Generally speaking, according to the design requirements to choose a certain tone pavement. Such as the requirement of gold hair warm luster, you can choose the red version as the pavement color; vice versa, you can choose blue; if you want both deep and luster, you can choose black pavement.
Fluorescent color printing refers to the use of spot-color plate printing fluorescent colors, using fluorescent ink printing, because the nature of the ink is different, the printed color is extremely eye-catching and bright. Used in design works, can produce a distinctive and unique effect.
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Post time: Mar-08-2023