Screen Printing.. What is it?

Screen printing is a printing technique that uses a woven mesh to support an ink blocking stencil. The attached stencil forms open areas of mesh that transfer ink as a sharp-edged image onto a substrate. A roller or squeegee is moved across the screen stencil forcing or pumping ink past the threads of the woven mesh in the open areas.
Screenprinting is more versatile than traditional printing techniques. The surface does not have to be printed under pressure, unlike etching or lithography, and it does not have to be planar. Screenprinting inks can be used to work with a variety of materials, such as textiles, ceramics, wood, paper, glass, metal, and plastic. As a result, screenprinting is used in many different industries, including:
1 Clothing
2 Product labels
3 Printed electronics, including circuit board printing
4 Thick film technology



http://en.wikipedia.org/wiki/Screen-printing

Screens are made by putting a chemical emulsion on a mesh surface. Vector artwork is taken from Adobe Illustrator or Freehand and printed out on a film type paper or vellum. The screen is then exposed on a light table with the artwork under it. The light solidifies the chemicals around the design, and where the light failed to pass through, the chemical breaks down. The screen is then rinsed out and what is left is the area where the light hit.
When you place an order for screen printed clothing there are two charges:
The first is a setup charge which covers the cost of having the design made into a screen. This charge is 'one off' as the screen is stored for future use. Therefore, if you wanted to place another order in the future with the same design there would be no setup charge.
The second charge is a 'per screen' charge which applies to each item that is customised. This charge basically covers the cost of labour, materials and our other manufacturing overheads.

http://www.indigoclothing.com/screen-printing/