Recently, the printing industry began to use non-printable substrates for printing. The printed materials show special printing effects. This is a special type of printing that is used under special circumstances. There are many types of special printing. The following types are available:
1. Ultraviolet (UV) printing
This is a printing method that uses ultraviolet rays to irradiate ink to dry it. The ink used is an ultraviolet drying ink. When the ink is irradiated with ultraviolet rays, it instantly hardens, and the ink film strength is relatively large. Therefore, for the printing and non-ink absorbency of synthetic paper such as printing paper packaging equipment using a low-cost thick paper paste liner, rapid drying of the printing, plastic is required. Printing processes, business form printing, and metal printing requiring harder metal printing are more suitable. The disadvantage is that the special solvent in the UV ink can swell the printing plate and the roller. Therefore, special equipment must be used. Ink is expensive and has poor preservation. It is also an inadequacy.
2, the printing of spices
This kind of printing is mostly used in cosmetics advertisements because adding a suitable scent to a pattern increases the added value of the print. This flavor ink is made by directly mixing the flavor into the ink. The appearance is similar to ordinary ink, but its inexpensive aromatic effect lasts longer. The fragrance of ink is encapsulated and encapsulated in microcapsules. When the printed matter is used, the fragrance is slowly overflowed due to the breakage of the microcapsules by hands or other forms.
3ã€Fluorescent and light storage printing
The ink absorbs ultraviolet light, causes it to receive visible light, causes a wavelength change, and reflects fluorescence. Printing with this ink is called fluorescent printing. After the ink is exposed to light, the light energy can be stored in a dark place. Printing with this kind of ink is called light accumulation printing. The visual effects of these two printed products are better. Therefore, posters and covers are printed on this type of process.
However, fluorescent pigments and light-storing pigments are expensive, and the printability of the ink is poor. To increase the color effect and visual effect, the ink layer must be thickened. In general, such inks have poor light fastness, and attention must be paid to the environmental issues of using such prints. In addition, in order to further improve the visual effects of prints, pearlescent inks (pearlescent inks) should be used for pearlescent printing.
4, uplift printing
The printing process is mainly used for printing such as braille embossing, and the printing pattern is entirely or partially convex, and has visual effects and sensory effects. When printing, a foaming agent that will make the printed pattern convex is used. After heating, the foaming agent expands, so that the pattern is raised (foam printing), and the resin powder can also be sprinkled on the printed pattern portion, and then It is heated and melted until it adheres to the pattern and is cooled, solidified and embossed, and it is stamped on the back of the print to form a relief.
In general, the foam printing and the stamper printing are inexpensive, but the pattern embossing amount is small, and the durability is low. Although the resin powder printing process can overcome the above disadvantages, the process is complicated and the price is high. The appropriate method should be selected according to the purpose of use.
5, OCR (optical character recognition device), OMR (optical type identification device) printing
Recently, the processing of bills such as transfer cheques and vouchers has been processed through the computer Icheon OCR and OMR. There are two ways to use these devices: plain text recognition and printed text recognition. The written frame is usually printed with normal ink. However, misunderstanding occurs when reading, but people can recognize the printing method using ink (ink color) that the device cannot recognize. Since the usable color is limited to the sensitive area of ​​the OCR device used, the choice of color is highly valued. In addition, due to the color change of the printing ink on the printing day, the contamination of the printing paper will cause misunderstanding, and management must be particularly strengthened.
6, high-precision, magnetic screen printing
In the existing flat-printing dot resolution to 175L resolution will be increased to more than 300L, it is called high-precision printing. The magnetic screen printing is to design the dot as a very fine rule dot, without the size. The reduction of the tone is achieved by the increase or decrease in the number of such dots.
Since the digital reduction ability of the fine portion of the tip point in the high-definition printing is enhanced, the corrugation or the like where the regular overlapping of the color dots does not occur, thus eliminating the trouble of correction. High-precision magnetic screen printing achieves the same results as expected, but due to the extremely small dots, the technical requirements for the plate printing process are extremely high.
7, high-sensitivity printing (6 to 7 colors)
In general, printing is performed by a subtractive four-color printing process using three primary colors (magenta, cyan, yellow) plus black. Green is formed by superimposing cyan and yellow. However, in actual printing, since the first printing ink (for example, cyan) is not dried yet, the next color (for example, yellow) is superimposed on it, so that the ink cannot be printed. Fully transferred to the final color (overlapping defects), it is difficult to restore the bright green.
In addition, in order to expand the scope of color reproduction, printing on the basis of the four-color printing process adds three colors of red, green, and blue and becomes seven-color printing. In addition, based on the four-color printing process, two colors of orange and green are printed to become six-color printing. Care should be taken when carrying out this printing process. Care must be taken to select the state of each dot. And careful analysis of 6-7 colors is particularly important to choose the state of the dot, in order to avoid the phenomenon of moire (such as the use of magnetic screen, etc.).
In addition, high-density printing using a high-concentration ink to extend the halftone dot area range, ultra-lightfast printing using ultra-lightfast ink, ultra-light-absorbing ink, and the like are employed in order to take into consideration that the printed matter used outdoors must have super-lightfastness. There is also the recent use of non-wood paper that considers environmental issues and uses soy oil for printing inks (soybean inks, various printing of all these special printings require varying degrees of chemical processes and technological levels. For this reason, first use To understand the characteristics of various special printing and effects, the added value of the print, the price difference, the difference between the pattern quality to make the right choice.