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. One color is printed at a time, so several screens can be used to produce a multicoloured image or design.
Plastisols are the most commonly used inks for printing designs on to garments, and are particularly useful for printing opaque graphics on dark fabrics.
Plastisol inks are recommended for printing on colored fabric. On lighter fabric, plastisol is extremely opaque and can retain a bright image for many years with proper care.
Water Based inks
Water based inks are screen-printing inks that are water soluble. Water based inks are much thinner and when printed with, will be absorbed into the fibers of the garment, becoming one with the shirt. This allows garments printed with water based inks to have little to no feel and retain the garments original flexibility and breathability. Water based ink prints should also last as long as the garment they are printed on. Plastisol is much thicker and sits on top of the garments fibers. This causes the garment to lose breathability and some flexibility.