Serigraphy
Screen printing is a printing technique used to reproduce documents and images on any material, and consists of transferring ink through a mesh stretched on a frame. The passage of the ink is blocked in the areas where there will be no image by means of an emulsion or varnish, leaving the area where the ink will pass free.
The printing system is repetitive, that is, once the first pattern has been achieved, the print can be repeated hundreds and even thousands of times without losing resolution.
Application
A mesh previously revealed by some design is placed that will be attached to a frame to keep it always taut and later to be held by an octopus or linear table that will have a support to print. Screen printing ink will be placed on the lower or upper part of the mesh without touching the design and moderate pressure will begin to be exerted with a squeegee, generally made of rubber, to apply it to an object.
The printing is done through a printer, framed in a frame, which is emulsified with a photosensitive material. By contact, the original is exposed to light to harden the parts free of image. By washing with water, the unexposed part is diluted, leaving those parts free on the canvas from which the ink is placed, which is spread over the entire canvas by means of a rubber rule. The ink passes through the mesh in the image part and is deposited on paper, cloth, glass, plastic, acrylic and almost any material.
History
The oldest screen printing techniques come from oriental culture. It is estimated that the first impressions were made by the natives of the Fiji Islands, in the year 3000 BC. C., using pierced banana leaves for the distribution of inks. The history of screen printing dates from this time.
Screen printing is an ancient printing system. Although there are no exact data, it is believed that it dates back to ancient China, in which, according to a legend, intertwined women's hair was used to which paper was glued, forming drawings that were later lacquered to make them waterproof. Later the material was changed to silk, and this is where its name comes from: sericum (silk, in Latin) graphe (to write, in Greek).
A hundred drawings made with this technique have been found in the caves of the Pyrenees. The Egyptians used screen printing for the decoration of murals and the interior design of temples and pyramids. In ancient times, decals were made that were applied to everyday items, plates, glasses, etc.[citation needed] In Europe it was used to print fabrics, in what was called "impression to the lioness", for being the place where this system was applied.
In Europe, screen printing became popular in the 18th century, and was used primarily to produce canvases for paintings and to print designs on fabric. In the 19th century, screen printing was used to print designs on glass and other materials.
In the 20th century, screen printing became even more popular with the development of new techniques and materials, and was used to print a wide variety of products, including billboards, t-shirts, business cards, and other promotional materials. Today, screen printing is still a widely used technique in the printing and graphics industry in general and is used to produce a wide range of high-quality printed products.
The first serigraphs on paper (advertising posters) appeared in the United States around 1916 with a note pending concession. The first patent granted is for Selectasine in 1918.
Guy Maccoy was the first to use the silkscreen technique for artistic purposes. He made the first two serigraphs of him in 1932; both were about 9 x 11 inches and he shot about 40 copies of each design. In 1938 he had his first solo exhibition, the first of silkscreens in a gallery.
It is in the United States, and with the rise of photography and chemical products, where it gains a spectacular boost; Because it is a very versatile method to be able to print on many materials, today thousands of articles processed with screen printing can be distinguished.
1960s
Artist Andy Warhol is credited with popularizing screen printing as an art technique. Warhol's silkscreens include his 1962 Marilyn Diptych, which is a portrait of actress Marilyn Monroe printed in bold colors. Warhol was supported in producing it by master screen printer Michel Caza, a founding member of Fespa.
Sister Mary Corita Kent gained international fame for her vibrant screen prints during the 1960s and 1970s. Her works were rainbow-colored, containing words that were both political and encouraging peace, love, and caring.
American businessman, artist, and inventor Michael Vasilantone began using, developing, and selling a multi-color garment rotary screen-printing machine in 1960. Vasilantone later applied for a patent on his invention in 1967, granted number 3,427,964 on 18 February 1969.[The original machine was made to print team logos and information on bowling apparel, but it soon made its way into the new craze of printing on T-shirts. The Vasilantone patent was licensed by multiple manufacturers and the resulting production and boom in printed T-shirts made this garment screen printing machine popular. Screen printing on apparel currently accounts for more than half of the screen printing activity in the United States.
Graphic screen printing is widely used today to create large batch or mass produced graphics, such as banners or exhibition stands. Full color prints can be created by printing in CMYK (cyan, magenta, yellow, and black).
Screen printing lends itself well to canvas printing. Andy Warhol, Arthur Okamura, Robert Rauschenberg, Roy Lichtenstein, Harry Gottlieb and many other artists have used screen printing as an expression of creativity and artistic vision.
Another variation, digital hybrid screen printing, is a marriage between analog screen printing and traditional direct-to-garment digital printing, two of the most common textile embellishment technologies in use today. Essentially, Digital Hybrid Screen Printing is an automatic screen printing press with a CMYK digital enhancement located at one of the screen printing stations. Digital hybrid screen printing is capable of variable data options, creating endless customizations, with the added capability of specific screen printing techniques.
Types
- Manual screen
- Serigraph semi automatic
- Circular serigraph
- Serigraphy in umbrella
- Automatic screen printing and textiles
Materials
It is worth saying that one of the reasons why silk has practically fallen into disuse is because no matter how much it stretches, when it takes on ambient humidity, it loosens again. Polyester, nylon or acrylic materials are commonly used.
The diameter of the threads that make up the gauze is uniform, but the gauze can be of different thicknesses; for more detailed work, more tightly woven gauze pads are preferred. For textile use, the number of threads is between 18 and 90 threads per linear cm. For use with solvent inks (non-textile prints) such as plastics, wood, metals or other materials, the meshes (silks) must be more closely woven, between 100 and 200 threads per linear cm. For the use of water-based inks, a number of threads of 34 to 62 threads is recommended; In some cases, depending on how diluted the ink is, we can use up to 90 threads.
The color of the gauze varies between white and yellow; the latter allow to obtain a better quality in the copy of the original, since they do not refract light. Silks can be monofilament or multifilament, "mono" they are more resistant and maintain the tension in the frame, giving them a very good dimensional stability, differentiating themselves from the multifilament, which are of low quality and little durability. The yellow mesh is widely used in screen printing on paper in weaves from 90 threads. In some cases they are used in 77-thread meshes and yellow for textiles to achieve better definition.
Preparation
During preparation, the gauze should be tightly attached to the frame. The tension in the gauze is very important to obtain good results. The tension can be irregular depending on the resistance of the gauze, for example if the chosen gauze is made of thinner threads, or if the gauze is mounted to the frame manually. The tension on the surface can be measured with a measuring instrument in newtons. A variation uses stainless steel cylinders, with tiny pores through which the ink passes, the pressure is exerted with a metallic cylinder housed inside the printing cylinder; this mode is used in textile printing and to manufacture the tracks of printed circuits.
After a long preparation process, the silk or fabric is completely stretched and ordered, giving it shape and regularity.
Process
1. As a first step, a suitable textile support must be obtained for the task to be carried out, depending on the final resolution of the print, for example, to print an advertising poster, muslin should be used, with approximately 20 threads, or if a tiny drawing is desired, use synthetic silk for screen printing, because it has more than 100 threads and therefore the holes will be smaller.
2. The preparation of the frame is very similar to the preparation of canvases for oil painting. The muslin or serigraphic silk is stretched to the wooden frame or to the metal frame, taking into account that the textile support must remain stretched until it does not present wrinkles, so that when printing it does not tear. Normally it is held with staples to the wooden frame tempering one point at a time and in a crossed way, this in order that the tension is even in all the corners.
3. They can be made in different materials, until a few years ago they were made with a transparent acetate sheet which was painted with a marker or Chinese ink, another method was with photocopies in transparent acetate, currently they are made using thermal printers designed exclusively for this purpose and that use exclusive high-quality film or with conventional printers on common 75-gram bond paper, which is painted on the back with almond oil, this makes the paper transparent and allows the plate to burn.
4. There are various emulsions on the market, depending on the ink to be printed with, the most common is the blue photoserigame emulsion (this changes a lot depending on the country where you reside), which is used for printing with inks based on water and benzine-based (varsol), there is also a red emulsion for printing with PVC-based inks, this is not resistant to water-based inks, these emulsions are activated with ammonium dichromate.
The colors of the emulsions should not be associated with a printing process, each manufacturer decides to add one color or another to their product in order to make it more visible, it is marketing.
To make the printing plates, it must be done in darkness or semi-darkness, or with the help of safety lamps using red or yellow light.
In some cases, depending on the emulsion manufacturer, we can emulsify with non-direct artificial light in order to see better. In no case should it be done in direct sunlight or UV light.
5. Ammonium bichromate is added to the emulsion (dichromate is prohibited in Europe and the US), in the amount indicated by the manufacturer, usually a few drops, it should be remembered that these materials are photosensitive, the most recommended is to store them in a dark place or inside black plastic bags, once the emulsion is prepared, it is spread evenly with a channel or a spatula on the frame with the silk tensioned and is allowed to dry in a dark place or with the help of from a hair dryer, once dry, the emulsion becomes somewhat transparent.
Thanks to the evolution of screen printing in the industrial and artistic world, manufacturers have begun to create direct emulsions, they are ready for use without the need to mix them with other products.
In some countries, diazo is used instead of dichromate. Diazo is a sensitizer that activates the emulsion and makes it photosensitive,
6. To reveal the plates a light source is used, normally a drawing table to trace, the emulsion reacts depending on the amount of light, so it is important to do tests to determine the exposure time, usually for a drawing table it is exposed for no more than one minute, you can also use a room focus, for this you must expose it for approximately 20 minutes or use drawer lamps built for this purpose, with several fluorescent lamps.
7. Having the frame with the dry emulsion, the photolithium is located, also called art, made under it, the objective is that the black parts of the photolitho do not let light pass to certain parts of the emulsified silk, therefore, in these parts the emulsion will not cure and can be washed later, it must be taken into account that there should be no space between the photolithography and the iron, for this, books or any element that presses the silk on the photolithography are used.
8. After the exposure of the plate proceed to develop, at this time you can leave the dark room towards a sink, gently rub the silk with your hand or with a brush, the parts that were not exposed to light will be easily diluted leaving the floss white, do not rub too much because all the emulsion will fall off. If the parts of the plate are not revealed, it is because the plate was overexposed, otherwise if the entire plate is blank, it is because it was underexposed and needed more time to react.
Uses
- The printing procedure is widely used to make reproductions of art and advertisements; in the reproduction of artwork, paintings, drawings, posters, etc.
Artistic screen printing is an original work, only serialized or multiplied, generally in very limited editions. It is done in collaboration with the artist and is signed and numbered in pencil by the painter himself. Great artists have used this Warhol technique. I look. Tapies. squeal. Chronicle Team. Gordillo. Saura. G.Wheel. canogar. Guinovart, etc. The National Library of Spain, the Museum of Engraving in Marbella, the Museum of Graphic Work in San Clemente (Cuenca) and Fairs such as Estampa in Madrid or SAGA in Paris, among other institutions, endorse the Graphic Work and contemporary art editions.
- In the pattern of fabrics, t-shirts, dresses, fabrics, ties, sports material, shoes, canvases, and all kinds of clothes.
- In plastic printing. Marquesins, panels, decoration elements, signaling and marking plates, control boards, etc.
- In wood and cork printing, for decoration elements, doors, furniture, panels, etc.
- In the printing of decals and labels. Calcomanías al agua y secas, etiquetas in autoadhesive complexes or materials (papel and polychloride vinyl (PVC)), vitrificable limestones for decoration of tiles, glass and ceramics.
- Crystal decoration, for mirrors and material, for all types of recreational and game machines, and in cylindrical for jars, bottles, containers, syringe, blisters, vases, etc.
- For the flocquer of all types of materials, in this case the adhesive is also applied by serigraphy.
- In the production of large-format wall posterry, external advertising fences, for the resistance of inks to ultraviolet rays.
- In all kinds of materials for decorating shop windows, counters, windows, interiors of shops, and, on any scale, promotional and advertising decoration elements.
- Direct decoration by means of enamels and vitrificables of clay, ceramic, porcelain, etc.
- Labels in aluminum, carulins, leathers, fabrics, etc.
- Production of printed circuits.
- Cork and wood decoration.
- Rotulation and marking with conveyors for vehicles and automotive material.
- Deck printing for folders, books, etc.
- Printing of market products. Pencils, lockers, etc.
Silkscreen prints can be detected because each color has some relief, and outlines of traced images, such as text, if we magnify them, will appear in a shape resembling the teeth of a saw.
It would be difficult to get a complete detail of all of them, since it evolves continuously precisely because of its possibilities of application in any type of support.
Some examples of techniques for screen printing on textiles are: Color selection (full color printing on the garment, either with light or dark backgrounds), Discharge printing: By corrosion of the color of the garment, Foil: Using sheets metallized paper, High Density (HD): High relief screen printing, these can be applied by also combining metallized sheets; Glitters, glitters, frosts and sparkle effects, Flock: which offers a velvet-like finish, etc.
Every day the companies that are dedicated to the textile industry force screen printing ink manufacturers to explore new techniques, invent or renew them, in order to always offer something innovative to the market.