Characteristics Of Offset Paper

Offset paper, also known as offset printing paper, is a relatively high-grade printing paper, which is generally used by offset printing machines for book or color printing. Offset paper is divided into single-sided offset paper and double-sided offset paper, and there are super calendering and ordinary calendering.

(1) The raw materials of offset paper and the performance of offset paper. Offset paper is generally made of bleached softwood chemical pulp and an appropriate amount of bamboo pulp. When processing offset paper, the filling and sizing are heavier, and some high-grade offset paper also needs to be sizing and calendering on the surface. Due to the principle of water-ink balance used in printing, offset paper needs to have good water resistance, dimensional stability and strength. Offset paper is mostly used in color printing, and in order to restore the tone of the original manuscript, the ink is required to have a certain degree of whiteness and smoothness. Offset paper is generally used to print albums, color illustrations, trademarks, covers, ring linings, high-end books and books, etc. In recent years, due to the improvement of people's culture and living standards, book materials have also developed to high-end, and more and more books and periodicals and books are printed on offset paper. Due to the advantages of offset paper such as white, crisp, flat and delicate, the text is clear after the book is made, and the book is flat and not easy to deform, compared with letterpress and newsprint books, the grade is very different, and it is welcomed by readers and users. The number of books and periodicals bound on offset paper will increase significantly in the future to meet the needs of the market.

(2) Specifications of offset paper. The specifications of the offset paper are the same as those of the previous two papers. For other specifications, please visit the national standard GB147 "Base Paper Size for Printing, Writing and Drawing", and the size error and deflection shall not exceed ±3mm. There are many kinds of quantitatives of offset paper, and the commonly used quantitatives are 60, 70, 80, 90, 120, 150, 180, 200, and 250g/m2. The offset paper used for printing books and periodicals is below 90g/m2, and the cover paper is about 70-200g/m2. Offset paper has the characteristics of crispness, smoothness, etc., and is easy to bind.

UNCOATED WOODFREE OFFSET PAPER

1) Any method can be used to achieve a good tidy effect when hitting pages.

2) Any folding machine can achieve good folding effect, especially suitable for high-speed folding.

3) The design of offset paper books and periodicals should be mainly based on triple-fold pages (four-fold pages must not be designed). It is best to fold twice (more than 80g/m2) before pasting, because the offset paper is thick and quantitative, and the bookbook is prone to figure-of-eight folds or dead folds that are not easy to stretch out if there are too many folds, resulting in uneven incisions and unequal quality problems of the book core after cutting.

4) When the number or thickness of the iron wire is the same as that of the letterpress paper, the diameter of the medium and large iron wire should be medium.

5) The viscosity of the binder is larger (thicker) than that used for bald paper, because the offset paper has a large amount and a smooth surface, and the viscosity is low (thin) and cannot be firmly adhered or falls off after sticking.

6) The hardcover book block of offset paper is not easy to round and ridge, especially when the post is thicker. Because the offset paper is slippery, it is easy to expose each bookpost after rounding and the front mouth is rounded in a trapezoidal shape; When the ridge is raised, the wrinkles in the creases cannot be smoothed due to manual knocking, resulting in defective products.

7) The offset paper is generally of higher grade to make books and periodicals, so the cover material should be better than the book core material, so that the inside and outside of the book can be matched.