Deal with color difference in catalog printing in China

It is impossible to avoid color difference completely in the catalog printing in China process. The key is how to control the color difference within a reasonable range.


1. Determine the upper and lower limits of product color with customers

When we print a catlogue for the first time, we should make the upper and lower limit of the standard color of the product, which will be "standard sample sheet" after being sealed by the customer. In the future, the production is based on the standard color of the standard samples (or the first batch of product samples), and the fluctuation of color shall not exceed the upper and lower limits of the standard.


2. Improve the sample signing and inspection system for the first and last parts

The inspection items of product color shall be included in the rules and regulations, so that the workshop management personnel can control the product color difference, and the unsuitable products shall not be accepted. At the same time, workshop managers and operators should also strengthen patrol inspection and spot check to ensure that products beyond the reasonable range of color difference can be found and handled in a timely manner in the production process.


Equipped with printing standard light source

Some printing factories do not use printing standard light source, which brings hidden danger to the color consistency control of catalog printing in China. The color of the product seen under the illumination light during the night shift is very different from that seen under the sunlight during the day shift, which is easy to cause the difference of printing color. Therefore, it is suggested that the printing workshop must use the printing standard light source for lighting, and if necessary, it should be equipped with a standard light source box.


Guarantee the quality of printing ink

Sometimes printing company encounter the situation that the ink color of printed products changes gradually after they are placed in the customer's place for a period of time, but the same phenomenon does not occur in the previous batches of printed products. This is generally due to the use of expired ink. The shelf life of ordinary ink is usually one year. It is easy to fade the printing products when using expired ink. Therefore, in the use of ink must pay attention to ink shelf life, adhere to the first in first out principle. In addition, in the printing process, we should pay attention to the use of ink additives. If the ink additive is used excessively, the color of the ink may change after printing.


Pay attention to the proportion and information transmission of spot color ink

In the process of printing production, it is often necessary to prepare spot color ink, while in the printing workshop, the color of the spot color ink is very different from that of the sample. The main reason for this kind of situation is that the ink ratio is not right. Spot color ink is made up of a variety of primary color inks, and most of the primary color inks are Pantone color systems, so when we prepare spot color inks, we often prepare them according to the proportion given on Pantone color card. However, it should be noted that the ink ratio on Pantone color card is not necessarily completely accurate, and there are often small differences. This requires the operator's experience, high sensitivity to ink color, more learning and practice, and continuous accumulation of experience in spot color ink configuration, so as to improve color sensitivity and achieve the level of proficiency in ink configuration.


Mastering the law of color change after special color drying

The printing color varies greatly. Some colors are very close to the sample color at the beginning of printing, but after drying, they are very different from the sample color. In addition, metallic inks such as gold and silver, due to the composition of the ink, its monochromatic or spot color ink prepared with it will also change after drying.

The printing process is a dynamic balance process, which will cause color difference every time the machine is stopped. Therefore, the unity of printing color has become an important printing quality index.