Some printing knowledge about coated paper

The surface of the coated paper is white, smooth and flat, with high smoothness and whiteness. It is a high-grade printing paper made of base paper coated with white paint. Coated paper is one of the main papers used by Chinese printers. Moreover, it is widely used in real life at present. The beautiful calendars, posters sold in bookstores, book covers, illustrations, etc. that everyone sees are almost all made of coated paper.

Coated paper mainly used for printing covers and illustrations of advanced books. It can be divided into single-sided coated paper, double-sided coated paper, matt coated paper and cloth coated paper. According to the quality is divided into A, B, C three grades. Commonly used coated paper is divided into various thickness specifications from 105 grams per square meter to 350 grams per square meter. In the sales of coated paper, the size of a single sheet is generally divided into two sizes: large (889mm×1194mm) and medium (787mm×1092mm). In the past, the quality of lithographic printing at that time was still low, and high-level painting artworks such as classical oil paintings were copied, and this paper was mainly used to print on photographic color copper plates (letters). Quantities are 100, 120, 150, 180, 200, 250 grams square meters, and the sheet packaging specifications are 787 × 1092 (mm), 880 × 1230 (mm).

The main raw materials of coated paper are coated base paper and paint. It is widely used by Chinese printers, the requirements for the coated base paper are uniform thickness, small flexibility, high strength and good water resistance. There should be no spots, wrinkles, holes and other paper defects on the paper surface. The coating used for coating is composed of high-quality white pigments (such as kaolin, barium sulfate, etc.), adhesives (such as polyvinyl alcohol, casein, etc.) and auxiliary additives. of. This kind of coating with high fluidity and high solid content is brushed on the base paper thinly and evenly by the coating machine, and then dried, rolled into a roll on the reel, and then sent to the super calender for pressing. Light finishing, finally slitting, paper selection, and packaging.

Coated coated paper is pressed with an old felt. In addition to its smooth surface and high whiteness, it also makes the printed graphics and pictures have a three-dimensional effect. Therefore, this coated paper can be widely used for printing pictorial, advertising, Landscape paintings, exquisite calendars, portraits, etc.