Recently, someone raised the question online: Why is the ink layer not bright enough when other colors are overprinted on silver ink on black paper? In this regard, the author has the following understanding and views for reference.

The so-called "black paper" belongs to the special paper type, and its surface gloss is generally not particularly bright. Therefore, if other colors of ink are printed on the offset silver base, it is best to choose high-gloss ink for printing and increase the printing pressure appropriately. In fact, the gloss of offset ink refers to the ability of the ink on the surface of the printed matter to concentrate and reflect light in the same direction under the action of light reflection conditions after drying through the oxidation conjunctiva. It is also the reflection of the brightness of the ink layer after drying on the surface of the substrate. According to the definition of ink terms in the national standard of the People's Republic of China: offset gloss ink (high gloss offset ink) refers to "offset ink with high gloss on the print". Therefore, glossy offset ink has a different gloss effect from ordinary offset ink, and its printing ink layer is relatively brighter and the price will be higher.

In addition, in order to better maintain the concentration of the ink, try not to add diluents, detackifiers and other additives to the ink to avoid thinning the ink, increasing fluidity, and reducing adhesion and gloss. If the printing ink is too thick and difficult to flow, transfer and apply, you can add some varnish oil to dilute and adjust it. The brightness of the printed ink layer will be significantly increased when the ink is prepared with varnish oil.

If the printing area is relatively large, you can use the "secondary overprinting process" for printing, that is, use the same color layout to increase the thickness and gloss of the printed ink layer through 2 overprints. If this effect is still not satisfactory, you can also apply a layer of light white ink or diluent on the surface of black paper as a primer, and then print silver ink to make the silver ink printing more saturated. In this way, overprinting other colors will significantly improve the brightness.

If the glossiness of the paper surface is relatively poor and the printed ink layer cannot be increased, you can consider using silk screen printing or embossing technology, because the printing ink layer in silk screen printing and embossing technology is significantly thicker than the ink layer in offset printing technology, and the printing ink layer has the significant advantage of higher brightness.