Coated paper was developed with screen printing. Because the surface unevenness of uncoated paper fibers is much larger than the diameter of the dots, some dots happen to be in the gaps between the fibers and cannot transfer the ink. On the paper, the image pixels cannot be reproduced in this part. After the paper is coated with the slurry and then calendered, the particles on the paper surface are smaller than the diameter of the dots, and the ink receptivity of the slurry is better than that of cellulose fibers. Therefore, the dots can be replicated correctly. Obviously, the printing performance of coated coated paper is better than that of uncoated offset paper.
The base paper of coated paper adopts high-quality newsprint roll or offset printing paper, and the high-grade coated paper adopts special base paper. The surface coating adheres firmly to the base paper. The paper surface is super calendered again, the coating is firm, no bubbles, no streaks, strong gloss and high smoothness. The smoothness of coated paper is generally above 600s, which is more than 10 times higher than that of offset paper. In this way, the coated paper can be in close contact with the printing plate, and the dots can be printed clearly. The pH value of the coated paper is about 7, which has no adverse effect on the lithographic printing wetting fluid, and has no adverse effect on the ink drying process.
The ink adheres quickly and dries quickly on the coated paper, and can also bring out the gloss after drying, the dot reproducibility is good, the ink layer is thin, the image is clear, and the dots are smooth. The dimensional stability of coated paper is also better than that of offset paper. Printing on coated paper can meet the requirements of overprint accuracy. The tensile strength and surface strength of the coated paper are also high enough to resist the greater tensile force produced by the more viscous ink film used. Due to the above-mentioned points, coated paper is often used to print high-end prints.
Supplementary note:
Coated paper includes gloss coated paper and matte coated paper. Generally, matte paper refers to matte coated paper, and coated paper refers to gloss coated paper;
The printing price of the two is the same, and the printing process requirements of matte paper are slightly higher, which may cause over-printing;
The surface of "matte paper" is not reflective, has good ink absorption, and the printing ink is relatively thick, so it takes longer to dry in the shade;
But if you use UV ink to print, you can completely solve the problem of long dry time (this ink is slightly more expensive than ordinary ink).
If you are interested in coated paper with full colour printing hardcover notebook, please contact us.