Lightfastness grades and lightfastness test methods

Fast ink level

The lightfastness level is generally divided into 8 levels, with level 1 being the worst and level 8 being the best. Most print buyers in Europe require that the red and yellow four-color inks have a light-fastness of 5 or above, and black and blue ones need a level of 7 or above; most of the inks used in the Asian region follow the Japanese hue, but most No more lightfast pigments are used, so the yellow and red light levels are only about 3, but Level 3 only belongs to the general level. Strictly speaking, it does not meet the requirements of lightfastness in Europe and America.

In general, the brighter colors such as fluorescent ink, yellow, blue light, gold red, orange, pink, purple, green lotus and other hue inks, most of the degree of light is below the 3 level; especially with a transparent lightening ink The light color inks that are formulated are extremely lightfast.

Fast test method

The traditional method of testing lightfastness levels uses blue wool as the indicator of fading. Therefore, it is necessary to use visual inspection to compare the shades of the grey proofreader and the blue cloth, which is difficult to print data.

Recently, the standards of print buyers in the United States used Lab and Xenon light boxes to measure the discoloration of analog prints after one year. In addition, the lightfastness of conventional lightfastness inks is not bright enough to keep up with Pantone's hue, and the new lightfastness varieties are brightly colored and can be deployed to the colors of the Pantone booklet, and can be attached to the color matching system database for computer color matching. Users of the system can deploy lightfast inks more easily.