Thursday 10th January 2013 By Brent Groot
Screen-printing is a process which uses screens with woven mesh that is able to produce and carry a stencil. The first step is to convert your design or drawing to transparent film. This is a positive image of your design that is used to create a stencil on the screen.
The film positive with your design is placed on the screen which has been pre-coated with photo sensitive emulsion. UV light is applied to the screen which reacts with the emulsion and hardens the area around the image. The screen is then washed out with water leaving a negative stencil of the image burned into the screen.
Originally silk was used for screen-printing, because the traditional name is silk screening. Nowadays synthetic threads are used, generally made from polyester.
Once we have a screen (E) and mesh (D) made with the stenciled image (C) on it, we need to get that image onto the t-shirt (F). This is done by placing the screen on top of the t-shirt. This requires some skill in placing the image in the correct position. The ink (A) is then forced through the mesh onto the t-shirt with the help of a squeegee (B).
There are many types of inks used with screen printing, we mainly use plastisol screen printing inks.
For more than one colour you will need more than one screen. Each colour will need its own screen. To make sure all the colour's line up correctly screen printers use a rotary multi-colour screen printing machine known as a Carousel. Full colour prints can be created by printing in CMYK (cyan, magenta, yellow and key line black) Which can be done with as little as 4 screens.
The screen printing process involves exact pressures, specialized inks, and heat curing that result in a long lasting design.
As you can see Screen printing has a highly detailed setup process that ensures the best quality print. Screen printing is often preferred over other processes such as dye sublimation or DTG Digital printing because of its low cost for large quantities and the ability to print on many types of garments.