The influence of metamerism on packaging printing

The same-color spectrum phenomenon has a great influence on the packaging and printing of goods. For example, in the printing and packaging industry, many of the exquisitely printed packaging boxes are uniform in color and accurate, but in the hands of major shops or users, they find that the colors are quite different. These will make users doubt the authenticity of the goods, require returns and even complaints, the credibility of the natural business is also damaged, and in fact this phenomenon is caused by the phenomenon of metamerism in printing, not counterfeit goods, but consumers do not understand the The reason, therefore, should pay attention to this issue in packaging printing.

Chromophores are difficult to avoid in packaging and printing, and they can only be controlled. We know that the final color effect of prints in printing is determined by the inks and substrates (such as paper), so they are also the main factors that cause metamerism, so we must pay attention to these two aspects. In terms of ink, due to the development of modern packaging printing toward multi-color and anti-counterfeiting, in addition to the yellow, blue, black, and black base colors, there are more and more spot colors. Different batches of spot-color inks are prone to metamerism after printing, so special attention should be paid to this issue in spot color ink modulation, which is an important factor affecting quality. Also, ordinary four-color printing uses different batches of ink, and even though the conditions such as the printing color sequence are the same, metamerism occurs. Therefore, regardless of spot color or four-color printing, the same brand of ink should be used as much as possible when printing. When the same color spectrum is found, it is timely reflected to the supplier, and it is required to provide the same ink in order to minimize or control the same-color different spectrum. phenomenon.

However, in actual packaging and decoration printing, there will be a certain color difference from three primary colors inks with spot colors or three primary dot dot area ratios with spot colors. For packaging and decorating printing, the color difference should be allowed when the replica and the standard sample (original) are matched with the metamerism color. However, the color difference between the replica and the original should be controlled as far as possible, and it should be limited to the allowable range. Inside. In the paper (especially colored paper), the nature of the paper has a great influence on the color of the ink printing, that is, the same ink printed on different paper will produce different color effects. Among them, the main factors affecting the color difference of ink printing are the whiteness, brightness, and absorption of the paper. Differences in properties such as paper color also cause metamerism. Therefore, it is very important to achieve the same color and the same performance parameters as the standard when producing paper. However, due to the current quality control of color in papermaking companies, most of them use only the color difference value under one observation condition to evaluate the color isochromaticity, regardless of the metamerism problem. Therefore, in the printing, a product should use as much as possible the same batch of paper of the same manufacturer to reduce and control the heterochromatic phenomenon caused by the paper. When looking at the sample with the customer, the observation of the color draft and the sample must be performed under the same standard light source to avoid color deviation due to different light sources, which should be noted in the printing.