Screen-printing
Screen-printing, also known as silk screening or serigraphy, is a printmaking technique that traditionally creates a sharp-edged single-color image using a stencil and a porous fabric. A screen print is an image created using this technique.
History
Silk screen printing has its origins in simple stenciling, most notably the Japanese form (katazome). The modern silk screen process originated from patents taken out by Samuel Simon in the early 1900s in England. This idea was then adopted in San Francisco, California, by John Pilsworth in 1914. He used a silk screen to form multicolor prints in much the same manner as silk screening is done today.
Silk screening took off during the First World War as an industrial process for printing flags and banners. The use of photographic stencils at this time further increased the processes versatility and encouraged wide-spread use.
It was adopted by American graphic artists in the 1930s. The Pop Art movement of the 1960s further popularized the technique. Many of Andy Warhol’s most famous works were created using the technique. It is currently popular both in fine arts and in small-scale commercial printing, where it is commonly used to put images on T-shirts, hats, ceramics, glass, polyethylene, polypropylene, paper, metals, and wood.
Printing technique
A screen is made of a piece of porous, finely woven fabric (originally silk, but typically made of polyester or nylon since the 1940s) stretched over a wood or aluminum frame. Areas of the screen are blocked off with a non-permeable material – a stencil – which is a negative of the image to be printed. That is, the open spaces are where the ink will appear.
The screen is placed on top of a piece of fabric. Ink is placed on top of the screen, and a squeegee (rubber blade) is used to spread the ink evenly across the screen. The ink passes through the open spaces in the screen onto the fabric being printed on the same surface. The ink is allowed to dry and then the process is repeated with another screen and different color of ink.
Stenciling Techniques
The most popular technique is to transfer a pre-drawn or printed image onto a screen using a type of photographic emulsion.
- The original image is placed on a transparent overlay. The image may be drawn or painted directly on the overlay, photocopied, or printed with a laser printer, as long as the areas to be inked are opaque. A black-and-white negative may also be used (projected onto the screen). However, unlike traditional platemaking, these screens are normally exposed by using film positives.
- The overlay is placed over the emulsion-coated screen, and then exposed with a strong light. The areas that are not opaque in the overlay allow light to reach the emulsion, which hardens and sticks to the screen.
- The screen is washed off thoroughly. The areas of emulsion that were not exposed to light – corresponding to the image on the overlay – dissolve and wash away, leaving a negative stencil of the image attached to the screen.
Photographic screens can reproduce images with a high level of detail, and can be reused for thousands of copies. The ease of producing transparent overlays, from any black-and-white image using a photocopier, makes this the most convenient method for artists who are not familiar with other printmaking techniques. The low resolution and size limitations of a photocopier make film positives necessary in professional screen printing environments. Artists can obtain screens, frames, emulsion, and lights separately. There are also preassembled kits, which are especially popular for printing small items such as greeting cards.
Advantages of Screen Printing
>Cost effective
>Long lasting
>Can print on colored fabrics