The cover generally uses 100G to bai120G double offset paper, and the du inner page generally uses 70G to 80G double offset paper, which is more cost-effective and cost-effective. If the cover is printed in four colors, the inner page is printed in black. We generally recommend that customers use double-copper paper for the front and back cover, because the surface of the double-copper paper is smoother, shiny, more upscale, artistic, and common double-coated paper is 105G, 128G, 157G, 200G, 250G, etc., but the instructions In general, we generally recommend the use of 128G and 157G double-coated paper for the front and back covers. Of course, the inner pages still choose 80G and 100G double-coated paper. In this way, the entire manual not only satisfies the texture, but also saves the company's costs. Of course, some companies have relatively high requirements on the manual, for example, the entire book is printed in four colors.