The difference between offset printing and letterpress printing
First of all, offset printing is different from letterpress printing and gravure, it is an indirect printing method with all the characteristics of indirect printing, that is to say, it is not in contact with paper directly, relative friction between forme and rubber blanket is smaller than printing plate and paper ( surface of offset paper is rougher than the surface of rubber blanket ), it can reduce wear of forme and improve the press run of forme. Secondly, compared with the printing pressure of letterpress printing and gravure, offset printing's pressure is much smaller, offset printing, no matter it is plate cylinder imprint or impression cylinder, they all have a dual function with cylinder-packing and impression. Surface characteristics of offset printing are different from letterpress printing and gravure's, the image area of offset printing is a thin resin layer, its hardness and strength are small. Thirdly, compared to letterpress printing and gravure, offset printing is an indirect printing method, its printing ink layer is thin. Besides, offset printing has water transfer fountain system while letterpress printing and gravure don't have. Because of the influence of dampening system and fountain solution, ink color of offset printing is flat and light. Offset printing is suitable for printing paper, it is the most important equipment for domestic periodicals and packing box production. Its printing plate material is PS, its price is 4o yuan a square meter, it can be recycled. At the same time, there is some recycle plate with bad quality, its ink is common offset printing ink with low cost. Letterpress printing is divided into resin printing and flexography printing. Letterpress resin printing mainly used for adhesive printing, its equipment is drum printing equipment with UV ink and high production efficiency. Letterpress flexography printing mainly used for producing cigarette box, diebold atm paper, paper cup, packing box, packing case. Water-based ink is with high efficiency.
According to printing plate material and consumable material, offset printing is with low cost.
For printing industry, different technology has different advantages, such as adhesive printing and letterpress printing have more advantages than offset printing because of high efficiency and labor cost saving. They also meet the requirement of customers.