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Screenprinting has its origins in simple stencilling, most notably of the Japanese form Katazome, used who cut banana leaves and inserted ink through the design holes on textiles, mostly for clothing. This was taken up in France. The modern screenprinting process originated from patents taken out by Samuel Simon in 1907 in England.This idea was then adopted in San Francisco, California, by John Pilsworth in 1914 who used screenprinting to form multicolor prints in a subtractive mode, differing from screenprinting as it is done today.
Screenprinting took off during the First World War as an industrial process for printing flags and banners. The use of photographic stencils at this time made the process more versatile and encouraged widespread use.
Process
A screen is made of a piece of porous, finely woven fabric (originally silk, but typically made of polyester since the 1940s) stretched over a frame of aluminum or wood. Areas of the screen are blocked off with a non-permeable material to form a stencil, which is a positive of the image to be printed; that is, the open spaces are where the ink will appear.
The screen is placed atop a substrate such as paper or fabric. Ink is placed on top of the screen, and a fill bar (also known as a floodbar) is used to fill the mesh openings with ink. The operator begins with the fill bar at the rear of the screen and behind a reservoir of ink. The operator lifts the screen to prevent contact with the substrate and then using a slight amount of downward force pulls the fill bar to the front of the screen . This effectively fills the mesh openings with ink and moves the ink reservoir to the front of the screen. the operator then uses a squeegee (rubber blade) to move the mesh down to the substrate and pushes the squeegee to the rear of the screen. The ink that is in the mesh opening is transferred by capillary action to the substrate in a controlled and prescribed amount, i.e. the wet ink deposit is equal to the thickness of the stencil. As the squeegee moves toward the rear of the screen the tension of the mesh pulls the mesh up away from the substrate leaving the ink upon the substrate surface.
Textile items are printed in multi-color designs using a wet on wet technique, while graphic items are allowed to dry between colors that are then printed with another screen and often in a different color. The screen can be re-used after cleaning. However if it is not, then the screen can be "reclaimed", that is cleared of all emulsion and used again.
While the public thinks of garments in conjunction with screen printing, the technique is used on tens of thousands of items, decals, clock and watch faces, and many more products.
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