The full range of offset and gravure

principle

Offset is divided into two types: water offset and waterless offset. Water offset printing is on flat printing plates, using the law of immiscibility and mutual repulsion of oil and water, so that the graphic part and the blank part on the same plane of the printing plate are respectively oleophilic and hydrophilic, and finally realize the graphic and text. The transfer. Since water and ink act on the same surface in a water-based offset, a water-based offset must ensure the balance between the two. Waterless offset printing is on the plate, with the ink-repelling silicone rubber layer as a blank part of the printing plate, printing with a special ink. Unlike water offset printing, waterless offset eliminates the fountain solution and improves handling performance.

Gravure printing is theoretically not as complicated as the principle of offset printing. It is only necessary to transfer the ink directly from the gravure plate to the substrate. The difference is that in the gravure printing process, a squeegee device is used, and in addition the graphic portion of the gravure plate is always lower than the blank portion.

According to practice, the dot area of ​​the gravure is generally larger than the dot area of ​​the offset printing. Because it reproduces the tone and gradation of the color by the thickness of the ink layer, it is not as exquisite and soft as an offset when reproducing an image such as a human face. . However, the prints printed by gravure printing are bright and full in color, strong in three-dimensional sense, and accurate in color reproduction, and are generally used for the printing of packaging products.

Both offset printing and gravure printing have relatively fixed printing fields, but calendars, high-end color periodicals, and paper packaging products are the focus of competition.

Technology

Both offset printing and gravure printing have relatively fixed printing fields, such as off-set sheet-fed printing and gravure printed plastic products. However, wall calendars, high-grade color periodicals, and paper packaging products are the focus of competition.

Offset printing and gravure printing have their own characteristics in the production process and are summarized as follows. Offset: 1 is suitable for short-run printing and frequently changing product design; 2 is suitable for short-period printing, especially for products with limited time, such as newspapers; 3 small footprint, low capital investment, and less incidental equipment. Gravure: 1 high printing rate, suitable for long live, can be repeated many times printing; 2 print quality is stable, reproducible; 3 can achieve double-sided printing roll material, to achieve the printing of special materials, such as plastic printing , metal materials, printing, etc.; 4 short ink Ink, the principle is simple, easy to operate.

But only from the perspective of printed products, the gravure printing product's visual effect is stronger and the quality is generally higher. Especially in recent years, the progress of plate making and engraving technology and the development of laser imaging have greatly improved gravure printing. Product consistency.

cost

The cost of raw materials is the most important one in the calculation of printing costs, including plate making costs, paper costs, ink costs, and energy costs. Since the production cost of gravure printing plates is much higher than that of offset printing plates, many people mistakenly believe that the cost of gravure printing is higher than that of offset printing. However, this is not exactly the case.

When printing in small batches, the cost of gravure printing is really higher than that of offset printing. However, for fixed repeat printing jobs, such as cigarette and alcohol packaging boxes, after printing multiple times, there is a difference between the two. The cost difference will quickly shrink, and even the cost of gravure will be lower than offset printing. When printing on thin paper, the gravure printing performance is better than offset printing, such as the effect of printing on the high-grade calendar paper of 52g/m2 with gravure printing. If offset printing is used, it needs to be achieved on a coated paper of 57g/m2. . Therefore, the difference between these two kinds of paper will make the printer more inclined to gravure printing when printing in large quantities. In addition, the long life, offset printing plate life is far less than the gravure plate cylinder.

In fact, offset printing and gravure printing each have a certain cost advantage, so we must choose according to the specific circumstances. If the number of printing jobs is large and the quality requirements are high, gravure printing is preferred. If the number of printing jobs is not large, only tens of thousands of prints or less, and the quality requirements are not high, offset printing can be preferred.

cycle

The production cycle is a measure of the choice of printing methods, while offset and gravure do have significant differences in the production cycle.

In fact, gravure has formed a set of strict and careful workflow, from the manuscript design to proofing, to the final printed matter, customers generally have to confirm step by step, in addition to the gravure printing plate generally requires a transport process after the completion of the production, ie From the platemaking point to the printing company, this will undoubtedly extend the production cycle and increase production costs. On the contrary, the workflow used for offset printing is much simpler and more direct, from the original design to the delivery of goods generally not exceeding two weeks. Therefore, at present, compared with offset printing, gravure printing does have obvious shortcomings in short-period printing. Even though the development and application of laser imaging technology and lightweight plastic rollers will shorten the gravure printing cycle, it is necessary to Offset printing is generally quick and impossible to achieve in the short term.

market

According to relevant information, in the global printing market, offset printing accounts for about 40%, gravure printing accounts for about 15%, flexo printing accounts for about 25%, and other printing accounts for 20%. Specific to the country, the proportion of offset printing will also increase, while the proportion of other printing methods will decrease accordingly. Of course, these data are not fixed. Due to the combined effects of various factors, the ratio in the short term depends on the specific circumstances.

The development trend of printing technology determines the proportion of various printing methods in the market in the future. According to the characteristics of global printing development, it can predict high-quality and short-run printing or can be the development direction of printing. All along, improvements in the accuracy of presses, improvements in printing processes and technologies, and improvements in the properties of printed materials have made the quality of print products an inevitable necessity. While the quality of printed matter has increased, the volume of short-run printing has also been rising. This is the opportunity created by the diversity of information media and printed products. Take the printing of domestic journals as an example. Some magazines with a circulation of more than one million copies 20 years ago may not exceed the current circulation due to the increase in similar magazines in recent years and the competition for reader resources by electronic media such as television and the Internet. 200,000 copies, in fact, this figure is the highest limit for the circulation of most periodicals in China. There may be a small number of periodicals with a circulation of more than one million copies. However, since they have established several printing points, there will not be much printing at each printing point, which should be of medium and short editions.

In view of the development trend of the market, Offset has introduced relevant technologies that meet the needs of market development, such as CTP systems without film, digital printing systems capable of on-demand printing, and so on. It not only improved the quality of printed matter, but also shortened the printing cycle, and quickly opened up new markets. The gravure printing that has traditionally been used for long-term survival and development has never even engaged in 1 million printed jobs. However, in the face of the current number of prints such as cigarettes and wine packaging, or the number of jobs that can exceed 1 million impressions, The less the situation, how to find a place in the competition with offset printing has become the main issue facing it.

Offset printing and gravure printing are very important printing methods in the printing market. They have different technologies and processes, and they have common areas in the printing industry. They are all rapidly developing. Its purpose is only one, that is, through continuous technological innovation, to adapt to the future development trend of printing, to provide customers with faster, high-quality, low-cost products. We should also appropriately select the appropriate printing method for the characteristics of the printing job to maximize profits.