dimecres, 4 de novembre del 2015

screen printing (serigraphy)


Screen printing, also known as serigraphy, is a method of creating an image on paper, fabric or some other object by pressing ink through a screen with areas blocked off by a stencil. The technique is used both for making fine art prints and for commercial applications, such as printing a company's logo on coffee mugs or t-shirts.

This form of printing is said to be based on the Japanese art of katazome, a form of stenciling with waterproof papers that was used in ancient Japan to copy an image. Some say, however, that the art originated in the Fiji Islands where banana leaves were used as stencils. The art as it is known today was patented in England in the early 1900s. The first commercial use of it in the United States occurred in 1914 when John Pilsworth developed a process to produce multiple multi-color prints from a single fabric screen, which was used to make multicolored signs and posters.
During World War I, serigraphy became the preferred method for printing flags and other patriotic banners because of its ability to create relatively identical and multi-layered images. More recently, it has been used by artists and manufacturers alike. In fact, most people probably own a serigraphed t-shirt and many have seen Andy Warhol's use of this technique in conjunction with photographic headshots of famous people, such as Marilyn Monroe.
Serigraphy is a relatively straightforward process. A piece of porous fabric is used as the screen. Originally, that porous fabric was silk, leading to the name silkscreen, but today, the more inexpensive alternatives of polyester or nylon are more commonly used. That porous fabric is tautly stretched across a wood or metal frame. Then, the negative areas of the image to be produced are blocked off on the screen with a non-porous material that can be paper, fabric, or plastic. This creates the stencil.
The screen, with the stencil in place, is then placed over the final product, such as paper or fabric. Ink, whether water- or oil-based, is spread evenly over the screen. A rubber squeegee is then used to press the ink through the porous areas and onto the paper or fabric below. If the design calls for multiple layers or colors, the ink from the first press is given time to dry, and the process is repeated with a different stencil or different ink color.