Whether it is Chinese painting, oil painting, or advertising painting, as long as the layered, especially the skin color of the screen is the original color separation and screen making, through offset printing, gravure printing, letterpress printing (flexo printing) screen printing Copied, but there are also non-dot printing of Colo version, woodcut watermark, and silk screen version.
Dot printing
There are two types of dot printing that represent the color image hierarchy
Amplitude modulation dot screen printing: Refers to the size of the dots to express the shades of the image within the unit area. Its weak point is that it is prone to moire.
FM dot screen printing: With the increase of computer computing functions, the FM dot screen technology has appeared. The FM screen technology is the same size of the dots in a unit area. The number of dots is the density of the dots to express the depth of the image. , FM outlets basically solve the moire problem.
Whether the above two screening methods are offset printing, gravure printing, embossing printing or screen printing, the image level can not be separated from the dots. Look at the printed matter with a magnifying glass. Technology, outlets are clearly visible on the replica.
Dotless printing
There are currently three methods for dot-free gradation printing: Colrotype printing, woodcut watermark printing, and silk-screen gradation printing.
Colrolithography is a photolithography technology invented very early. It uses glass for platemaking, also known as glass plate printing. The process is:
Grinded glass: grind the smooth surface of 10mm thick glass, wash, dry and coat the bottom layer.
Primer coating: coat the ground glass with a layer of sodium silicate and protein solution mixture and liquid as the primer layer. After drying, apply photosensitive adhesive.
Photosensitive adhesive coating: coat a layer of dichromate and Mingjiao photosensitive liquid on the dried bottom layer, and then dry it. The drying temperature is between 40 ℃ and 60 ℃. The glue will produce fine wrinkles.
Exposure: Exposure and development of the continuously adjusted negative film negative film and photosensitive film. The unexposed photoresist is washed away during development, and a water-absorbing layer is formed during printing. The photoresist in the light-receiving part has different levels of sensitivity due to different levels of the photoresist, and the thickness of the ink absorption layer is also different.
Printing: Printing on a special platform with a Coro plate printing machine. Its structure is a round flattened type, which is inked with rubber rollers. The applied ink requires good fluidity and low viscosity.
Colo printing is a negative version of negative film. The hardened layer on the plate image with a greater amount of light is greater, the more wrinkles are, the more ink is adhered, and the darker the tone when printing. , The brighter.
Although Coro Printing is a dot-free printing method recognized in the world, it is difficult to reproduce fine images due to insufficient subtle levels. In Japan, there is also Koro printing, which only makes prints such as certificates.
The woodcut watermark was created and invented in China, and it is my traditional printing method. It is recognized in the world, and its process is:
Outline (color separation)
(1) When sketching, first cover the transparent and water-impermeable film on the original work, and then copy the picture faithfully on the film.
(2) Then cover the goose skin paper on the gummed paper that is drawn into a manuscript, separate colors according to different hue, and draw dots, lines, color blocks, inscriptions, seals, and picture levels into a manuscript. As many shades as there are in the original work, there are as many manuscripts as possible.
The sketching technicians must not only have a high degree of painting skills, but also have a deep knowledge of traditional Chinese painting. When sketching, it is necessary to make a decision on the number of editions of the original and the shade of the original, the style and artistic characteristics of the painter and the size of the screen, and how to print.
Carved wood plate: Post the manuscript on the wooden board, and then engrave and make a plate after it is dry. Each manuscript is carved into a wooden board. It takes dozens or even a hundred plates to print a picture. The engravers must be familiar with the ancient and modern paintings, and carefully understand the original works in order to be able to handle it freely, and to engrave the lines and levels in a beautiful way. Printing: Brush the engraved wood blocks in sequence. The method is to first print the protruding part of the wood block (that is, the picture part), and then spread the rice paper on it, and then hold the brush and print on the rice paper. As many wood blocks as possible are printed on this rice paper as many times as necessary to make a finished product. It requires the printer to be familiar with painting techniques. Before printing, it is necessary to analyze the speed, slowness, lightness, and weight of the original pen, and the difference in color density, lightness, dryness, and wetness. According to the rendering and retouching of the original, etc., the brush will be processed appropriately while printing, so that the printed products will reproduce the characteristics of the original pen and ink. Silk-screen version of level printing can achieve the reproduction of Chinese paintings, oil paintings and advertising paintings without any dots. The process method:
Original layered color separation: the original is divided into multiple slices in different levels of yellow, magenta, cyan, and black by the computer. If each color can be divided into 10 levels, each color can be divided into 10 different levels of negatives.
Silk-screen printing: 40 film negatives are numbered to form 40 silk-screen printing plates. The requirements of this printing process on the tension of the stretched screen, the selection of the screen, the coating of the photoresist, the exposure time, and the development should be basically the same as the requirements of the screen printing to make a fine screen.
Printing: According to the screen number of different layers of negative film, it is printed in order. This printing method is called layer printing, and some are called ladder printing. In fact, the layer is printed layer by layer from shallow to deep. It can not only achieve the purpose of expressing the level, but also achieve dot-free printing, which can be used to copy the ancient paintings in France, such as in France, to give real artistic value. The French oil painters entrusted their oil painting works to the screen printing company. After this method of screen printing and copying, they were signed by the painter to make them valuable.
The offset printing, gravure printing, embossing printing, and screen printing of the above-mentioned FM dots cannot be used in the copy because of the dots in the replicas. The Colo printing without dots, due to the lack of layers, limited space, and low printing volume It was gradually eliminated.
Although the woodcut watermark copy image can achieve the effect of being fake, but the production cycle is long, the amount of printing is small, and the cost is high. The processes of sketching, adjustment, and printing are more complicated and have many manual operations. Although the technicians are experts, each color tone It is also difficult to achieve consistency, color shift is easy, and there are also inaccurate overprinting and deformation.
The screen printing process uses a computer to analyze the manuscript, scan the manuscript in layers, and output the layered negative film. The screen printing and printing are carried out in layers. The copied crafts have high precision, rich subtle levels, and good reproducibility. Dot-printed glue products can't be compared with it, even the non-dot-column and woodcut watermarks can't be compared with it.
leather corner sofa,Corner Sofas,large corner sofa,corner chaise sofa
Guangzhou LoPhiDa Co.Ltd , https://www.guangdongwidinlsa.com