A brief introduction to metamerism

Print color effects are always a major aspect of evaluating product quality. This situation is often encountered in printing. The colors inherent in the design or the manuscript are inconsistent with the colors after printing and copying. Even the differences are very large. There are no abnormalities in the inspection of printing equipment, materials, and operating techniques. This is actually a metachromatic phenomenon in color science.

In nature, each type of object has its own fixed optical properties, so that in the full spectrum of sunlight, the color of each object is fixed. However, when the spectral composition of the light source changes, the object does not show its inherent color under the light source, but presents different colors. This kind of color is the same color under a certain light source, but under the other light source, the phenomenon that its color appears changes is called metamerism.

The same-color different spectrum phenomenon has a great influence on the color printing, and the color package printing is completely a method of copying the original with the same-color different-spectrum color. Usually, three colors of CMY are used to simulate the reproduction of various colors in nature, but to the human eye, the final cells can stimulate the feeling of RGB color.

Chromophores have a detrimental effect on color printing, so care should be taken to add control during printing. However, metamerism has its value in special printing. For example, in the packaging and anti-counterfeit printing, the heterochromism phenomenon has its advantageous aspects.

In addition, the same-color different spectrum ink is also a special anti-counterfeiting ink newly developed and developed. The graphic and text printed by the ink can produce different graphic and text colors under the irradiation of different light sources or changing the light direction. At present, it has been widely used in the printing of banknotes and coupons. For example, the fourth set of renminbi issued in China has used the same color difference ink. If this ink is used in the packaging and printing of high-end goods, it will also enhance the product. The anti-counterfeiting effect.