1, ink color
The color of printing ink depends on the choice and composition of pigment. For the needs of commodity and commodity packaging, human beings have developed new ink color varieties and improved the quality of traditional color hues.
The ink color on the substrate is often influenced by its own chroma and the influence of ambient light. For example, it is green, red, white and so on under the standard light source. But if the ambient light or illumination conditions change, such as red light into the white ink film will make the white packaging printing ink red. The surface decoration color of any package is not to be known at all. According to the knowledge of color chromaticity and so on, we should study the law of color change of ink film constantly, so as to print a good product.
2. The concept of the same color spectrum in printing and decoration.
It is not enough to meet the needs of printing and printing ink color varieties. It is necessary to pass certain color matching process to get the requirements of serialization of finished product color ink on the market. After printing, new color hues were obtained, which not only accorded with the normal law of packaging printing, but also accorded with the law of color matching.
In order to achieve the above requirements, the concept of the same color spectrum is proposed. Ink samples with different spectral distribution are very important for color matching of color package printing ink. That is, the use of different ink color can be transferred out of the same ink color varieties.
It can only be approximated to a certain extent in practical color matching and can be evaluated by the shape of spectral reflectance coefficient curve. The more similar and coincident the reflectivity coefficient curves of the two samples, the more intersections, and the more proof that the color matched is similar to the sample. The color difference can be calculated through two ink sample chromaticity for quantitative analysis. It shows the extent of their chromatic spectrum.
3. Basic knowledge of color deployment.
In the packaging printing ink system, the binder is colorless or with a slight color liquid, refractive index and water is very close, so the binder has a certain degree of transparency, when adding pigments and fillers, because pigments and fillers blocked the light from shining, resulting in changes in the optical properties of the ink.
When sunlight enters the yellow ink film, it means that it absorbs the blue spectrum of sunlight and emits yellow and green light. When the reflected yellow and green light encounters the blue pigment particles again, the reflected blue light will absorb only the remaining green light.
After a series of reflection and refraction, it only reflects green ink ink film. Therefore, we call this printing ink color mixing subtractive mixing (absorb each other's required wavelengths without being reflected by the absorption spectrum), which is the origin of the mixed color (or compound color).