The principle of image printing Networking Outlets Dot shape Corner Dot density Haze Number of outlets Mesh FM Network (FMS) Network percentage (in number) Erasable Gel ink Pen ,Gel Ink Pen ,Gel Pen , Neutral Pen with eraser Tonglu shangmei pen industry co.,ltd , https://www.shangmeipenindustry.com
Within a certain area of ​​the image, there are several grids separated by the X-axis and the Y-axis (the number varies depending on the device and the needs). These grids are the group pixels that make up the image. Each cell is a pixel unit. A pixel composed of monomers forms a variety of images in a continuous or discrete manner, which is a net in prints. Through the change of the dot area and the amount of ink, the original image with different shades is reproduced on the paper.
For printing paper or laser photolithography, the photographic plate is binary. In the printing process, ink is printed on paper with pure ink, and ink is pure paper. In the process of laser photolithography, the film is exposed by the laser spot, black spots are formed at the exposed positions, and the white areas formed by unexposed areas are almost pure transparent white. Photographs are hierarchical. Scanner input photos generally have 256 levels. In order to print the gradation effect of a photo on a binary paper, you must add screens. This type of screening is performed during the electronic layout or photolithography process that the front end begins. For example, during the scanning process, the image scanner completes the screen-hanging of each sample pixel of the image file, the output of the finished film or the appearance of the laser, etc., so that on the printed paper, these dots are formed on the film. The dots are transferred into ink dots of different sizes and different shades to form an ink stick model. We use the instrument or magnifier to view the same film as a separate black dot and white background. From a distance, we can display a certain gray scale. This is screening.
The smallest units (such as photoprinting, laser photocopying, and printed publication images, black and white dots) are the network dots. Dots are the basic pixels that make up a print artwork. For example, a web of news photos and prints is made up of a diverse group of outlets. These outlets can determine the size of the outlets according to the image. Tones that are the same in color (such as a black one) consist of continuous dots of the same size. Inconsistent shades (like a pattern of woods and distant mountains), that is, the original patterns are indifferent, generally described in layers, and consist of discrete dots of different sizes and numbers. Regardless of the network, it plays a role of accepting and transmitting ink during the printing process. The size of the dots determines the size of the ink to be transferred. The depth of the dot density determines how much ink is delivered.
The geometry of the formation refers to the geometry of the individual network points. The traditional printing dot shape is determined by the screen structure. Commonly used square, diamond, round, double point and so on. Different from the traditional screen, in the electronic publishing system, it is defined by computer software. Commonly used are: geometric shape and square shape. Round, chain and line. You can select samples as needed during the layout process.
Web angle refers to the angle between the vertical line and the horizontal line at the center of the network. The mesh angle indicates the arrangement direction of the mesh points, and the mesh angle reflects the arrangement of the mesh points. With a magnifying glass it can be clearly seen that the dots of the texture are arranged horizontally-vertically, and we may call this direction the main direction of the web. Commonly used web angles are mostly 90 degrees (ie, 0 degrees), 15 degrees, 45 degrees, and 75 degrees. Since the 45 degree screen angle is best viewed from a visual point of view, it is generally used in monochrome printing. In color printing, for the four-color version, C (cyan), M (magenta), Y (yellow), and K (black) are required, and the main directions are 15 degrees, 45 degrees, 90 degrees, and 75 degrees. Angles are linked to the net. These angles are the corners of each edition.
Density is a measure of the characteristics of an object that absorbs light. It is the ratio of the amount of light that is shot and the amount of reflected light or transmitted light. It is represented by the decimal equivalent of transmittance or reflectivity. Dot density generally refers to two kinds: one is the dot density of the printed matter (usually lower than the film density, about 1.7 or so); one is used for making PS plates and other films (photographic plates, laser photo films, generally from 2.5 To 5.00 or less). Printing films are divided into color separation films and monochrome films. For color separation films, according to international and national standards: "The transmission density of the center of the network should be at least higher than the transmission density of the transparent film 2.5 (film base plus fog), both of which are measured under white light. The transmission density of Kiga's fog can't be 0.06 higher than that of the zero-adjusted densitometer when the measurement channel has no film.
Fog is the density of gray that exists on the white transparent part of the photographic film. The density is caused by the quality of the film and the quality of the process. The reasons are:
A. Film's own fog.
B. During the exposure of the photographic film, the optical lens is not clean, the focus is not true or the exposure is too strong.
C. Photographic film development process, due to liquid medicine reasons such as liquid temperature is too high, too thick, too slow.
D. If the photographic film expires, it will expire if it exceeds the expiration date.
E. Light leakage during operation.
Refers to the number of dots in the horizontal or vertical direction within a certain area (usually measured in square inches). For example, the resolution unit of a laser imagesetter is DPI, which is the number of dots per inch. Such as ECRM1545 Phototypesetter, the resolution is 1524DPI, that is, in the horizontal or vertical direction, there are 1524 points in one inch.
The mesh is also called the dot line number. Refers to the number of one-way parallel lines within a unit area (in inches or centimeters). (Traditional platemaking, also known as the screen line number L, reflects the resolution of the dots. Usually the number of printed pages is It is determined by its height from 60 meshes, 80 meshes, 90 meshes, ... 200 meshes. In general, the higher the number of lines, the greater the number of dots per unit area, the more pixels, and the details of the print description (levels However, if the accuracy of the equipment is not sufficiently high, the quality of the raw materials will not be up to standard. Therefore, due to printing conditions such as machine accuracy, ink quality, paper quality, etc., the number of meshes printed in general color newspapers is less than 133 mesh. At present, 120 or 133 orders are used in Hong Kong and Taiwan, and mainland China is mostly 100. For fine prints, 160-200 orders are required. The higher the number of lectures in general, the smaller the printed matter is, the finer the prints, and the more manuscripts are. However, due to the aforementioned conditions, the number of outlets is high, which may be due to the low level of paper ink and printers, and technical reasons such as ink and ink imbalance, excessive pressure, and the expansion of outlets beyond technical standards. Paste, run color and other phenomena.
When the resolution is fixed, the number of meshes is inversely proportional to the level. Since the resolution of the back-end imagesetter is fixed, the mesh number is higher. The smaller the dot design, the lower the level, which will directly affect the printing quality. In general, there is a addition rule. For example, when it is guaranteed that the printed matter can reflect the 100 levels of each color of the original, 1000 DPI can be printed up to 100 meshes at most; 1500 DPI can be printed to 150 meshes. If the resolution of the imagesetter is low, a higher number of meshes cannot be used, otherwise the greater the level loss, the longer the time required to output images and perform other operations on the images.
Compared with the traditional screening methods described above, the fixed point center distance and the use of different network points correspond to the changes in density and gradation. Since the 1980s, foreign countries have proposed “frequency-modulated screening†and have corresponding software available. . FM networks can also be referred to as random sites, dithered sites, or webless printing. Different from the general outlets, the traditional outlet frequencies are fixed. During the printing process, the level change is reflected by the size of outlets. The FM network is fixed in size, and changes in the level are reflected by changes in the frequency of the outlets. The FM network can make the duplicated image smooth and beautiful, and also can make the resolution-less photosetter (such as ECRM-1030) able to improve the clarity of prints and eliminate the “rhizard†phenomenon through this type of dot. The rear-end plate making and printing processes need to be adjusted accordingly. The main problem is that it is difficult to reproduce the dark tone level of the image, and the highlight layer is rough and requires high raw materials.
The percentage of outlets refers to the proportion of outlets in the unit area (usually in square inches). If the fixed area is set at one hundred percent, then the entire area is in the field, which means 100% outlets. According to each level, the 5% difference between steps is to be reduced or increased, which may be 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40% in order. , 35%, 30%, 25%, 20%, 15%, 10%, 5%, in addition, less than 5% and between 100% and 95% of the dot difference in the total of 22 levels. China's printing plants are accustomed to using decimal points for calculation, generally from 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, respectively, that 10% to 1 point Into the point. The accuracy of the number of outlets is critical to the quality of the printed matter. In general, for quality standards such as dot, film density, fog, and dot expansion, there are dedicated density testers to test. In daily work, the percentage of outlets can be measured by using a dedicated transmissive densitometer on the viewing table to accurately measure the finished film and using a reflective densitometer to accurately measure the finished product. Without a densitometer, we can use a magnifying glass to determine the percentage of outlets by visual inspection.
10% dot (10%) The white area between two black dots can accommodate 3 dots.
20% dots (20% dots) The white area between two black dots can accommodate 2 dots.
30% dots (30% dots) The white area between two black dots can accommodate 1.5 dots.
40% dots (40% dots) The white area between two black dots can accommodate 1.25 dots.
50% dots (50% dots) The white area between two black dots can accommodate 1 dot.
60% dots (60% dots) The white area between two white dots can accommodate 1.25 dots.
70% dots (70% dots) The white area between two white dots can accommodate 1.5 dots.
80% dots (80% dots) The white area between two white dots can accommodate 2 dots.
90% outlet (90%) The white area between two white outlets can accommodate 3 outlets.
100% outlets (ten percent) black and white.
Source: Printer