2. In the color cards of various brands of ink, all are marked with the three primary colors, basic colors, and standard colors. When color matching, why use three primary colors or basic colors instead of standard colors? This is because the three primary colors and the basic colors are composed of a single pigment, and the standard colors are the basic colors. Each of the standard colors is derived from two or more pigments, and the colors formed by the standard colors cannot Satisfies the 3 attributes of the color. That is, the hue, brightness and purity are not as good as those of the three primary colors or the basic colors. The more gray and dark the color is, the older the color is, and the less vivid it is.
(1) Hue: It reflects the inherent color appearance of color, and is the main difference between color and color. That is, a certain wavelength of light represents a certain fixed hue. The hue is different, and the wavelength of the light wave is also different. The color measurement is represented by H.
(2) Brightness: Reflects lightness and darkness. There are two kinds of brightness for color, one is the degree of lightness and darkness between each color. This is due to the different wavelengths of light waves of different colors. After reflection, the degree of stimulation to the human eye depends on the tennis film. From the green to the entire visible spectrum, Yellow is the highest and lightness is high, so people are very sensitive to green, from orange to red, green to purple, the brightness decreases; the other is the color of the same hue, the height is different, that is, they appear to be deep between them or due to different brightness. There are shallow, the more white, the greater the brightness.
(3) Purity (saturation): It reflects the degree of color close to natural color. The closer to natural color, the higher the purity, and vice versa. In the measurement of computer color separation, it is represented by C.
Third, the color matching step to get a sample (sample), should be done from the following steps:
1. According to the material of the substrate, determine which type of ink to use and then select the brand of ink.
2. According to the sample draft, first select the main color, the main color is selected, then see what color, that is, the secondary color.
3. Color Matching: Remove the main color after thorough mixing and then add the secondary color. In the addition of the secondary color, be careful, add a little bit more, and then use the same parameter when the color of the deployment is close to the sample. The mesh number, the same screen thickness as the photosensitive layer, and the same scratch hardness, etc.) were tested until it passed.
4 ink sample preparation process method points:
(1) Analyze the sample, determine the main color and sub-color (color head), select the ink with the percentage of a certain weight with the reference color (three primary colors).
(2) In the color matching process, the principles of light and dark (white, yellow, orange, red, purple, blue, cyan, green, and black) are used. In particular, colors with strong coloring power can only be added to quantitative 70% to 80%. When the hue is close, it should be added with care and accurately weighed. The main color is added in 100 g units and the secondary colors are weighed in 0.1 g accuracy.
(3) Toning is to adjust the main color first, when the main color is close, then adjust the second color, when it reaches 90% or so stop, proofing (must pay attention to uniform deployment, stirring full). The light color is generally a little deeper than the sample draft, while the dark color is the wet ink that is lighter than the sample draft because the light color is lighter than the wet ink, and the dark color is generally lighter after being dried.
(4) Record in detail the usage data, name, code number, etc. of each color ink.
(5) Comparison of viewing sample and manuscript: Note that printing of the same kind of process parameters on the same material as the sample (sampling) shall be performed in a dedicated color box or a standard box without direct light.
(6) Correct and compare and confirm.
(7) Magnify deployment.
Note: Different types of inks cannot be mixed. Spot color solvents must be used to adjust the viscosity.
5. Determination of color:
(1) Light source: The same color has different effects under different wavelengths of light, so it is recommended to use standard light sources when detecting colors. Standard light sources include D65, D50, and A. (To be continued)