Printing Paper for Offset Printing Books and Periodicals

Name and Origin Printing paper for offset printing books and periodicals is a new type of paper developed to meet the rapid printing requirements of offset rotary printing machines, replacing letterpress printing paper. In addition to possessing the general properties of letterpress printing paper, this type of paper also needs to meet the specific requirements of offset printing processes. It is named after its primary application in printing books and periodicals.

Uses and Specifications Printing paper for offset printing books and periodicals is primarily used for offset printing of various publications, such as books, magazines, and documents. With the significant progress in printing technology in China, offset printing machines are becoming more widespread, leading to an increasing demand for printing paper for offset printing books and periodicals.

This type of paper is classified into three grades: A, B, and C, depending on the requirements of the publication. It comes in three different weights: 52g/m2, 60g/m2, and 70g/m2.

Common Raw Materials The main raw material for printing paper for offset printing books and periodicals is reed pulp. Large areas of reeds grow in the Panjin region in the northern part of China, and the Dongting Lake area in the southern part also has considerable resources of reeds and rushes. In Europe, the best fiber quality comes from the Danube River region in Romania, but the reeds in both the northern and southern parts of China are of good quality, although reeds and rushes often grow together, making them difficult to distinguish. Additionally, attention should be paid to the degradation of reed fibers in China, as there is a phenomenon of deterioration. While it is possible to use entirely reed pulp for making printing paper for offset printing books and periodicals, adding a portion of chemical wood pulp (especially bleached sulfate coniferous wood pulp) can enhance the paper’s quality.

Technical Requirements Printing paper for offset printing books and periodicals is suitable for monochrome and two-color offset printing of books, documents, and magazines. The main technical requirements include:

(1)Minimal stretch deformation: Due to the multiple overprinting processes on offset rotary machines, if the paper has significant stretch deformation, accurate overprinting becomes impossible, resulting in blurry images and unclear outlines, affecting print quality.

(2)Good surface strength: Since the ink used in offset printing generally has higher viscosity than that used in letterpress printing, offset printing paper’s surface strength should be greater to reduce the impact of fluffing on printing efficiency and print quality.

(3)Adequate ink absorption and ink application: With the continuous increase in printing speed, offset printing paper for books and periodicals must have good ink absorption. Otherwise, the printed text may be blurry, or the printed image may be unrecognizable, leading to waste. Due to the overprinting in offset printing, the paper should have a certain ink application to prevent damage from the action of wet water during printing.

Click to learn more about book printing, sticker printing, medicine box, hardcover book printing, PE bag, Bible printing, paper bag printing, catalog printing, and printing in China.

(4)The paper should be flat, with a uniform fiber structure and consistent color. Each batch of paper should not have significant differences.

(5)The paper surface should be free of visual defects that could affect printing use, such as sand, hard lumps, folds, wrinkles, various streaks, spots, transparent points, cracks, holes, etc. There should be no paper fragments, remnants, damage, or recessed corners inside the flat paper. Additionally, printing paper for offset printing books and periodicals has specific requirements for paper whiteness and dust.