Ink light resistance grade standard and test method

The light fastness of the ink is also the light resistance, and the light resistance refers to a property that the ink maintains a stable color after seeing light. The ink with poor light resistance will fade after a period of light exposure. Some printed materials meet the requirements when printed in the printing house, and the color shift phenomenon occurs after being used for a period of time at the customer. This is mostly due to this.

A printing company has a customer who requires sunscreen ink to print, in order to prevent discoloration of printed matter. The customer's product type is mainly based on coated paper printing. After the glue is applied to the gray board, the product like the folder, the product will be discolored after being placed at the window for a period of time. The customer proposed to print with sunscreen ink, the level is above 7th level. Who can have the standard of sunscreen ink and how is the level tested?

In general, the ink resistance of the ink manufacturer should refer to ISO12040-1997 Graphic technology - Prints printing inks - Assessment light fastness using filtered xenon arc light. Ink sunscreen level is generally divided into 8 levels, 8 is the highest level: 1 level very poor; 2 level poor; 3 levels moderate; 4 levels relativelyly good; 5 levels good; 6 levels very good; 7 levels excellent; 8 levels outstanding.

The light fastness level is generally divided into 8 levels, the 1st grade is the worst, and the 8th grade is the best. European printing buyers mostly require red and yellow four-color inks to have a lightfastness of 5 or higher, and black and blue require 7 or more; the inks used in the Asian region mostly follow the Japanese hue, but most None of the pigments are more resistant to light, so the yellow and red lightfastness levels are only about 3, but the 3 grades are only general grades. Strictly speaking, they do not meet the lightfast requirements of Europe and the United States.

The test can be tested using a xenon lamp aging tester/sunlight color fastness tester. The traditional method of testing the lightfastness level uses the blue wool fading as an indicator. Therefore, it is difficult to compare the gray proofing scale and the fading depth of the blue cloth by visual inspection. Recently, the standard for printing buyers in the United States used Lab and Xenon light boxes to measure the fading of simulated prints after one year.

Many ink factories have begun to pay attention to the light fastness of inks, specializing in the production of light-resistant inks, and testing according to standard regulations. In the past, the color of the fast-fast ink was not bright enough to keep up with Pantone's hue, and the new light-resistant variety was colorful, and it could be blended into the color of the Pantone color book, and it can be attached to the color matching system database to make the computer color matching system Users can easily blend lightfast inks.