Since the five printing methods are different, the appropriate printing method must be matched according to the needs of the printed matter, and the printed matter can receive the expected effect.

1. Letterpress printing

There are many texts, few photos and pictures, many opportunities for text modification, and a small number of prints---prints between hundreds or thousands are suitable for letterpress printing. The number of type printing should not exceed 30,000, and the number of fine pictures should not exceed 70, 80,000. Printed pictures must use pink paper to get perfect dots. Therefore, you can't use cheap paper to print pictures and hope to achieve exquisite results. When using the letterpress layout form, the joints of the lines are easily separated and disconnected, which is a common disadvantage. In addition, too much pressure during printing or too soft the surface of the pressure cylinder will cause embossed protrusions on the back of the finished printed sheet, which will greatly reduce the quality of the printed matter.

2. Offset printing

The difference between offset printing and letterpress printing is that letterpress printing screen images must be made of paper with a smooth surface. Offset printing does not have this need, as long as the paper quality is not too rough. The printing screen effect is softer than the letterpress, and it is easy to print round dots.

Resin plate or nylon plate is another printing plate that can withstand abrasion more than the above-mentioned several types of plates. The printing times can reach one million, which can be said to be the longest life of the printing plate. However, the method of using this type of printing plate is slightly different from the ordinary offset printing method, that is, it does not require a wetting system, so it is named "dry offset printing."

Generally speaking, the more pictures there are in the printed matter, the larger the picture area, and the better it is to use offset printing instead of letterpress printing. As mentioned above, the effect of using offset printing to print pictures is better than letterpress printing, so the general color printing and four-color printing all use offset printing instead of letterpress printing.

Three, gravure printing

Gravure printing is suitable for printing high-quality and expensive publications. Whether it is four-color or black and white pictures, gravure printing can highly resemble photographic photos. Because the plate-making fee is expensive and the printing volume must be large, it is the least used of the five printing types in Hong Kong.

Fourth, screen printing

Because the screen printing ink is particularly thick, it is most suitable for printing with special effects. The quantity is not large and the ink needs to be thick. It can also be printed on three-dimensional, such as square boxes, boxes, round bottles, cans, etc. In addition to paper, the bottom can also be printed on cloth, plywood, plastic sheet, metal sheet, glass, etc. It is commonly used to print pennants, T-shirts, Watson boxes, soda bottles, circuit boards, etc. The above-mentioned various printing features are not available in other printing methods.

Five, offset paper printing (rubber printing)

Offset paper printing is only suitable for printing plastic bags, hand pumping, large and small plastic packaging. The input printer of the printed sheet is not a single sheet but a roll, and it must be cut one by one after printing. The fineness of printed dots and lines is far inferior to letterpress and offset printing. It can be seen that offset printing cannot be used to print books and publications.