How to control printing color difference for poster printing?

In the daily poster printing production process, how to maintain the consistency of printing colors has always been a difficult problem for printing production personnel. Many printers in China have also experienced customer complaints or even returns due to the color difference of printed products, resulting in serious quality accidents. Let the professional China printing company explore how to control product color consistency during print production.

Establish a perfect color management system

As we all know, it is impossible to completely avoid chromatic aberration in the printing process, and the key lies in how to control the chromatic aberration within a reasonable range. The first step in the printing process to control the color consistency of products is to establish a complete color management system, so that operators can understand the standards of qualified products, including the following two points.

Determine the upper and lower limits of product color with customers

When we produce a product for the first time, we should formulate the standard upper and lower limit of the color of the product, which will be designated as “standard proof” after the customer seals the sample. In the future production, the standard color of the standard proofs (or the first batch of product proofs) will be used as the basis, and it is strictly stipulated that the fluctuation of the color cannot exceed the upper and lower limits of the standard. That is to say, confirm the color difference standard range with the customer in advance, and at the same time ensure the color consistency of the product, give the production staff a reasonable color fluctuation range, so that the product color standard is more operable.

In addition, it must be noted that the “standard proof” of the customer's sealing sample should be replaced regularly, so as to avoid the deviation between the standard proof and the actual printed product due to a long time.

Improve the first and last part signature, inspection and sampling system

If you want to further ensure the implementation of the color standard, the inspection items of product color should also be included in the “Product First and Last Part Inspection System” and “Inspection Quality Record”, which is convenient for workshop managers to control product color differences. Unsuitable products are resolutely rejected to pass. At the same time, workshop managers and operators should also strengthen inspections and random inspections to ensure that products that exceed a reasonable range of color difference can be found and processed in a timely manner during the production process.

With the development of printing detection technology, the accuracy of color difference detection equipment has been greatly improved compared to the past. Conditional printers in China can introduce relevant color difference control equipment to realize digital color difference management.

Equipped with printing standard light source

Some printers in China do not use printing standard light sources, which brings hidden dangers to the color consistency control of printed products. The color of the product seen under the lighting source during the night shift is very different from the color of the product seen under the sunlight during the day shift, which can easily lead to the difference in printing color. Therefore, it is recommended that the printing workshop must use the printing standard light source for lighting, and if necessary, be equipped with a standard light source box.

Guarantee printing ink quality

Printing companies sometimes encounter such a situation: after a printed product is placed at the customer's place for a period of time, its ink color gradually changes, but the same phenomenon does not occur in the first few batches of printed products. This is generally due to the use of expired ink. The shelf life of ordinary ink is usually one year, and the use of expired ink is prone to fading of printed products. Therefore, when using ink, we must pay attention to the ink shelf life and adhere to the principle of first-in, first-out. In addition, in the printing production process, we should also pay attention to the amount of ink additives used. Excessive use of ink additives can also cause changes in the color of the ink after printing. Therefore, when using various ink additives, it is best to communicate with the ink supplier first to determine the correct range of additive proportions.