Paper is one of the most important raw materials for printing plants. As a printing material, the choice of paper is very important. So how do printing companies buy paper? What are the key points in the process of purchasing paper? Let's study together. Paper has many characteristics, which have different effects on printed matter. First of all, ink film, the thickness of ink film affects the gloss of printed matter. The thicker the ink film, the better the gloss of printed matter. The glossiness of printed matter varies with the thickness of ink film.
No matter what kind of paper, the amount of gloss that improves with the increase of ink film thickness has a certain limit. Secondly, the size of the gap on the paper is the basis of ink absorption. The size of the gap determines the balance between the time of ink absorption and the fixing time of the bonding material, and affects the composition of the gloss of the printed matter. The gloss of ordinary printed matter decreases with the enhancement of paper absorption ability. The smoothness and glossiness of paper also affect the glossiness of printed matter. The smoothness of paper is high, and the gloss of printed matter is high. The paper itself has a good gloss, so the reflectivity of ink film is high, thus the gloss of printed matter is high.
There is also a correlation between paper smoothness, gloss and absorptivity. The size of paper dots also affects the color change of printed matter. The ink content of printed matter will affect dots, and the contrast of printed matter will be affected if dots become larger with the increase of ink content. The dot change will make the contrast smaller, and the details and clarity of the printed matter will suffer. Usually, the ambiguity of printed matter is actually the dot problem, not the inadequate accuracy of the picture as we usually say. Unless it is really a picture of very high quality, a large part of the reason is that the contrast caused by dot enlargement becomes smaller, the image darkens, and the dot is ambiguous. The smaller the dot diameter, the more precise the printed matter, and the higher the smoothness requirement of the paper. This is a key point of paper purchase, and in the process of practical consumption, can also adjust the performance of ink to adapt to paper. Generally, the registration request of printed matter is higher, and the error is controlled within 0.05 mm.
There are many reasons for the inaccuracy of color printing, but the change of water content of paper is a very important factor in the process of printing. The change of paper moisture content may lead to shrinkage or shrinkage of paper, and the change of water content may change the size of part of paper, resulting in other forms of deformation, such as curling, folding and so on. In order to make the paper moisture content on the whole paper adhere to the average divergence, and adapt to the temperature and humidity of the printing workshop; at the same time, in order to reduce the paper's sensitivity to environmental humidity and improve the stability of paper size, it is necessary to stop the humidity adjustment (hanging) treatment before printing.
Paper is one of the important raw materials of printing plants. The quality of paper directly affects the quality of printed matter. The characteristics of paper are different, so the printing compliance of paper is different. In the process of choosing and purchasing, the printing house chooses the printed matter layer by layer according to the request of the printed matter, in order to achieve the best printing effect.