Comparison of the characteristics of letterpress printing and offset printing

Typography

There are many characters, few photos and drawings, there are many opportunities for changing the text, and the number of printed products is not large—prints of hundreds or thousands of thousands should be printed in letterpress. The number of type printing should not exceed 30,000, and the fine picture electronic version should not exceed 780,000. Printed paper must use powdered paper to get the perfect dot. So you can't use cheap paper to print your pictures and you want to get beautiful results. With the letterpress version of the letterpress form, the intersections of the lines are easily separated and disconnected, which is a common disadvantage. In addition, when the printing pressure is too high at the time of printing or the surface of the pressure cylinder is too soft, the back of the finished product sheet will have embossed relief, which will greatly reduce the quality of the printed matter.

Offset printing

The biggest difference between Offset Printing and Letterpress Printing is that the surface of the letterpress printing screen must use smooth-surfaced paper. Offset printing does not have this need, as long as the paper is not too rough. The screen printing effect is softer than the letterpress, and it is easy to print round dots. The resin plate or nylon plate is another type of printing plate that is more wear-resistant than the above-mentioned several plates. The printing plate can reach 1 million times, which is the longest life in the plate. However, the method of using this kind of printing plate has been slightly different from the ordinary offset printing method, that is, without a wetting system, it is named "dry offset printing". Generally speaking, the more pictures in prints, the larger the area of ​​the picture, the more appropriate to use offset printing instead of using letterpress printing. As described above, the effect of printing pictures using offset printing is better than that of typography. In general color printing, four-color printing uses offset printing instead of letterpress printing.