Screen printing is a printing technique
whereby a mesh is used to transfer ink onto a substrate, except in areas made
impermeable to the ink by a blocking stencil.
A blade or squeegee is moved across the screen to fill the open mesh apertures
with ink, and a reverse stroke then causes the screen to touch the substrate
momentarily along a line of contact. This causes the ink to wet the substrate
and be pulled out of the mesh apertures as the screen springs back after the
blade has passed.
Screen printing is also a stencil method of print making in which a design is imposed on a screen of polyester or other fine mesh, with blank areas coated with an impermeable substance. Ink is forced into the mesh openings by the fill blade or squeegee and by wetting the substrate, transferred onto the printing surface during the squeegee stroke. As the screen rebounds away from the substrate the ink remains on the substrate. The process is also known as silk-screen, screen, serigraphy, and serigraph printing. One colour is printed at a time, so several screens can be used to produce a multi-coloured image or design.
In order to make screen printing sustainable a non-toxic sustainable ink has to be used. The best sustainable ink to use within screen printing is water based ink. Water Based Inks Do Not Contain Toxic Chemicals. Most commercial screen printers print garments using plastisol inks, which are easy to use and last well. However, plastisol inks contain PVC and phthalates that are harmful to the environment and have been linked to numerous medical disorders.
