Small craftsmanship in flexo platemaking (below)

(Tools of Trade) 8. If a colorimetric test sample is to be screened for solid areas or fine text and lines, a total of more than 400 different combinations can be made based on the number of screens, screen angles, and dot sizes. s Choice. With so many choices, what kind of cyberspace is best? This depends on the printing conditions. Here's a simple way to introduce it to you. This is a sample test. This wide color patch includes 83 different printing plate hole blocks, 8 unscreened solid color blocks (for the purpose of comparison) and 7 halftone color blocks. The user prints a test sample of the color standard on the printing machine, and selects the kind of cell with the best effect from the printing result. The printed test sample is generally evaluated visually. The user can first observe the characteristics of the color patches in the test sample within the normal viewing distance (the length of the arm), such as the smoothness of the solid area and the clarity of the text. Next, use a magnifying glass to carefully examine its characteristics, such as "halo." Some users also use colorimeters or spectrophotometers to measure color patches to determine which type of cell has the highest density value after printing. Nine, choose and use In the process of selecting and using network points, you can follow the following two basic principles: 1. Under a certain printing conditions, select and use the best network effect of copying. 2. Selecting and using a network point that has good copying effect under various printing conditions. It also means choosing the most common network point. From a purely technical point of view, despite the wide variety of printing conditions, it is always possible to have a cell with the best reproduction effect under certain specific printing conditions. Therefore, in order to determine the best cell under certain printing conditions, the test sample needs to be printed and analyzed under various printing conditions. In addition, there is another method that is "Best Common Cell Method." That is to say, to find out which kind of nets are better for copying under various printing conditions. It has been done first that the test samples are printed under various printing conditions, and then the printed ones are examined one after the other to determine which one of the printing plate cells has a printing effect that is significantly better than that of the solid color blocks. Through research, we have found that, under various printing conditions, the copying effect of a general-purpose cell is much better than that of an unscreened solid-colored patch. Therefore, this kind of cell can be used for various printing conditions. Further inspections have found that the best plate points determined under the condition of “minimum ink transfer amount” are the most suitable ones for various printing conditions. We know that cyan inks have the poorest transfer performance. Therefore, if the printer uses an anilox roller with 400 to 800 lines per inch, only the cyan ink and the 800 line/inch anilox roller are used to print the test sample. The results obtained are applicable to various color inks and various line number anilox rollers. If the amount of ink transfer is slightly larger, it may be that the copy effect of some other cells will be better than the copy effect of the general cell, but the copy effect of the universal cell is far better than that under any kind of printing conditions. Over the effect of the non-screened solid color blocks. X. Looking to the Future In the flexo printing, the application of printing plate nets may become a big breakthrough. More than 40 years ago, people invented anilox rollers with inked holes on the surface. This made a tremendous contribution to the development and progress of the flexographic printing process. After that, there have been almost no such great achievements. The current printing plate network technology can be regarded as a comparable breakthrough, which may play a great role in promoting the development of flexographic printing technology, but it is also difficult to predict. At present, the following two aspects are under study: 1. Edge mask technology. 2. Apply plate points in the halftone area. The edge mask technique removes the overlap between the cell site and the adjacent line (or field) portion. The goal is to eliminate jagged edges (these jagged edges may be caused by the use of plate pockets). When using an anilox roller of 400 to 800 lines/inch, the sawtooth effect is significantly less than that of the gravure (150 to 200 lines/inch). This kind of edge mask technology can be selected by the user, because some users think that these overlapping areas play a certain role in eliminating halation. Currently, plate points can also be used within the “100% tone value” of the halftone image. The dull tone after duplication is smoother and has a higher density value. Therefore, the user is now trying to Apply this technique within the tone range. At the same time when this technique is applied, if a typical hybrid screening technique is used in conjunction with it, it is possible to use the plate points in the user-specified halftone area. Quantum hybrid technology enables the printing plate network to achieve the effect of “fade out gradually”. In this way, it is impossible for the naked eye to distinguish where the starting point of the printing plate is. This makes the transition of the tone more natural, smoother and darker. The area has a higher density value, while also allowing the halftone image to remain 100% halftone at all times, without a bit of realism (the ability to maximize detail).