Types and characteristics of papers

Glossy paper: Its biggest feature is that the printed photos have a glossy surface. In addition, it has the texture of traditional photos and good moisture-proof effect, so the printed photos look very comfortable. Suitable for printing high-quality photos, as well as record covers and report covers.

Glossy paper: Compared with glossy paper, glossy paper is more detailed and has a strong luster on the surface. But it doesn't mean it is better than glossy paper, because it is not as thick as glossy paper. Relatively speaking, its price is relatively low, and it is suitable for printing some artistic photos with large print volume and materials with many words, but the artistic photos should be kept well and no wrinkles are allowed.

Smooth photographic paper: its surface is covered with resin layer, which is very smooth, bright white and shiny. Photos printed with it can produce maximum color saturation and bright colors.

High resolution paper (thick photographic paper): This kind of photographic paper is characterized by its "thickness", so its price is higher than other photographic papers. This is mainly because its coating is thicker than ordinary inkjet printing paper, its surface is very flat, and its printing effect is also very good, which is close to the quality of traditional photos. If you want to create bright and dazzling images, this is an excellent choice, such as using it to print thick posters and some craft paintings.

Swelling photographic paper: It is a swelling coating formed by coating polyvinyl alcohol (PVA) on the base paper. Its surface is made of gelatin, polyvinyl alcohol and other polymers, forming an ink absorption layer. When printing, ink drops are sprayed on the surface of the ink absorption layer, and the polymer absorbs moisture and expands to show various colors, which has a very good color reduction effect. However, due to the limited expansion speed of polymers, the drying speed is very slow. Especially the new six-color piezoelectric printer, the printed image has serious accumulation defects, and the clarity is not satisfactory. Its water resistance is poor, although it can be improved by adhesive modification, but its ink absorption is reduced, that is, the ink absorption and water resistance are contradictory. Generally speaking, its production cost is relatively low, but its ink absorption performance is poor, drying is slow, and it is not waterproof. After printing, it is necessary to cover the film, and there are many later processes, which increases the cost.

Cast-coated waterproof photographic paper: its coating is micron-sized silicon dioxide, and its brightness and whiteness can reach the level of traditional photographic paper after special process treatment. It is the flagship product of some powerful inkjet material manufacturers in China. It has a waterproof coating, but the base paper is the same as the expanded photographic paper, so the overall waterproof performance is poor, and the photographic paper will be deformed to some extent after printing high saturation pictures; At the same time, the fineness of the coating is not enough.

Gap photographic paper: its base paper, like traditional photographic paper, is RC paper (both sides of the base paper are coated with waterproof PE coating, so it is also called RC high-gloss photographic paper. Its coating is made of nano-silica material, forming extremely fine inorganic-organic composite particles. After ink is ejected, it is quickly absorbed by micropores similar to honeycomb, hence the name gap photographic paper. Due to the special micropore structure, the coating has strong ink absorption and can also show a good layering for the darker parts. Drying is also very fast, and you can touch it directly when you come out of the printer; Its coating material is very fine and high brightness, which can match high-precision photo printing. At the same time, the waterproof performance is also good. If the photo is accidentally splashed by water, just dry it and keep it as it is. To sum up, the advantages of gap photographic paper are "three highs and one quick": high gloss, high waterproof, high ink absorption and quick drying. Gap coating is the development direction of inkjet printing media, and the image quality of its printing begins to compete with the traditional silver halide photographic paper.

brand

Epson, Canon, Kodak, Lexmark, Xerox, Hewlett-Packard.

Historical changes of papermaking raw materials

Paper-making, as one of China's "Four Great Inventions", was born in the Cai Lun era of the Eastern Han Dynasty. At that time, the raw materials for papermaking were rags and fishing nets mainly made of hemp. During the Tang and Song Dynasties, raw materials such as hemp, bark and straw were used for papermaking. When China's papermaking technology spread to the west, the raw materials for pulping were mainly flax and straw. In recent 100 years, with the development of industrial civilization and the emergence of modern pulping technology, wood has gradually become the main raw material for western papermaking. It is found that wood is more suitable for modern mass production than other raw materials: the fiber shape is superior to other raw materials, and it is easy to manufacture various high-quality products, with high production efficiency, easy pollution control, compact volume and convenient transportation and storage. In less than 100 years, the proportion of wood in the structure of papermaking raw materials rose from 10% in 1880 to 93% in 1970. At present, the world's major paper-making countries, such as the United States, Canada, Japan, Sweden, Finland and so on. Almost all of them use wood fiber to make paper. In the past, countries that mainly made paper from grass, such as Spain, have a long history of producing straw pulp, the output and quality of paper have not been improved for a long time, and there are few varieties. Since the 1960s, paper-making timber forests have been built. By the end of 1970s, when the ratio of vegetation in Spain was changed to 3:7, the output of paper and paperboard increased by 4.4 times. On the contrary, some countries that continue to focus on grass are facing great difficulties in the development of paper industry. These conditions strongly show that wood papermaking is technologically advanced and economically reasonable.

In China, due to the lack of understanding of the nature of the paper industry after the founding of the People's Republic of China and the scarcity of forest resources in China, there are many areas where wood is needed for economic construction. Many people mistakenly think that using wood to make paper is a waste of resources, and using grass as raw material is the most suitable for China's national conditions. By 1958, a "grass-based" raw material policy was formed, which raised the "dispute between vegetation and trees" to the height of political line. However, history has proved that this raw material policy does not conform to the industrial characteristics of the paper industry, which hinders the development of the paper industry in China and becomes the chief culprit of the paper industry in China.

In the 1970s, people of insight in the paper industry pointed out that "China's paper industry should take the road of giving priority to wood", so a new round of "dispute between plants and trees" was announced, and it was not until the mid-1990s that the country finally defined the road of giving priority to wood.