Screen printing
Screen printing is a printing technology that allows you to print not only on paper but also on textiles, plastics, glass, ceramics, metal, leather and other materials, as well as on irregularly shaped objects.
Screen printing screen.
The technology is somewhat similar to offset printing, as the image is made up of many points where there is either no or no image, but differs in the type of intermediate carrier used - instead of a printing plate or plate, a template made of a fine screen is used. The formation of the image in the sieve is done by a photographic process (contact exposure), in which some of the holes are plugged and the others remain unclogged. Ink passes through the closed holes, while it does not pass through the closed ones. Screen printing is used to a much lesser extent than offset printing, but this technology is therefore applicable to many more materials and is used in advertising souvenirs and in industrial production [1].
Screen printing technique
The screen printing method is widely used in the visual arts.
History
As early as ancient China, in the Song Dynasty (960-1279 BC), there was a technique resembling screen printing. It was at this time that the world's first printed money appeared. The printing of durable images has been an art that has been passed down for generations, and the masters of this technique have had a high status in society.
Over the years, this technique has been adopted by many other countries and cultures in Asia and especially by Japan. From this time date many successful and detailed images of the then possibilities.
For centuries, the East has kept the secret of precision printing of images on textiles and parchment.
Screen printing in Europe and America
It was not until the end of the 18th century that screen printing made its way to Europe and America through trade and cultural exchanges with the East, and in particular the silk trade. In the beginning, this technology met with disapproval in the West. Europe and America adopted screen printing technology and began to use it widely only a century later.
Inks
Screen printing inks have special properties that actually entitle screen printing to exist. No other printing process can use as wide a range of inks as screen printing.
For example, screen printing ink is not suitable for use on plastic. Glass printing ink has a completely different composition than fabric printing ink.
When choosing an ink for screen printing, it is important to carefully consider not only its components, but also its properties, ie. that the ink not only has a satisfactory quality in use (eg good mixing properties with other inks, quality printing properties, etc.), but also has good service properties such as light resistance, abrasion resistance, abrasion resistance, water resistance, etc. It should not clog the screen openings and the ink print must dry evenly. The ink must be resistant to strong sunlight (do not fade or change). It must also have good adhesion to the material and be resistant to washing.
Additives (additives) are usually included in the ink to improve its performance. These include substances such as: driers - accelerating drying, softeners, plasticizers - improving their elasticity, adhesives and antifoams. Refills can also be added to this list, which are often added to the ink to give it more "body" (density). The opposite effect of driers is achieved by retarders or retention agents. These are actually slow-evaporating thinners that neutralize the rapid drying of the ink. Retarders or retention agents are used when printing very fine details and in manual screen printing or if the temperature in the workroom is too high.
Colors
Almost all manufacturers of printing inks offer recipes for hundreds, even thousands of colors and shades with a percentage of mixing the basic colors of a series of inks.
Subtractive mixing of colors occurs when dyes are mixed. When the blue color mixes with the yellow, the blue pigment reflects the blue light rays, but then they are filtered (passed) through the yellow pigment, so the result is a green color. Partial color rendering is the separation of the light components that the human eye sees, as happens when perceiving a halftone print.
Important moments in the process of mixing colors are color saturation and color fastness. By color saturation is meant the depth, the density of the color. The terms light, brightness or gray values indicate how light or dark the color is. The impression of light interference in color is obtained when someone compares a sheet of orange paper in sunlight with the same sheet in the shade. Although the saturation remains the same, the orange color of the shade looks darker than it is in sunlight. Color saturation is determined by measuring color density. The measurement is performed with a densitometer - a device for measuring densities with sample printing (test printing).
Literature
Parygin AB The art of silk-screen printing. Twentieth century (history, phenomenology. Techniques, names). - СПб .: СПб ГУТД, 2010. - 304 с. - ISBN 978-5-7937-0490-8
Bigeleisen J. I. Screen Printing: A Contemporary Guide. - New York, 1972. (eng).
Types and properties of screen printing inks Archive of the original from 2016-09-09 in Wayback Machine.