Screen printing is a printing technique which has a high learning curve, but once you have learned how to screen print, you will enjoy fine-tuning the process for many years. This article is a rough explanation of the process of screen printing.

Screen printing uses a woven mesh to support an ink-blocking stencil. The stencil is made of open areas of mesh which will move the ink, when pressure is applied, through the mesh. A squeegee or roller utensil is pushed slowly across the stencil, causing the ink to flood past the threads of the woven mesh into the areas not covered from the ink by the stencil. Any areas which to be kept blank have to be covered with an impermeable substance so the ink does not reach them.

Your screen is made from porous mesh which is stretched tightly over a frame. You will block off selected areas of your mesh screen to create your stencil. As the uncovered areas are the places which will absorb the ink, you can think of your stencil as a negative of the image you will screen print.

Before you apply ink, put both the mesh screen and its frame through a ‘pre-press’. You will move an emulsion across the mesh, using an exposure unit to burn away extra emulsion. This leaves a clean area in the mesh to be used. Next you will coat the surface you are printing (called a pallet) with “pallet tape”, so that you can control the ink from staining the areas you mean to leave blank. The screen and frame are then lined with tape also. Split Tape is the best to use with plastisol inks and some UV and water-based inks. You can also use Blue R-Tape and masking tape if you want something more aggressive, but you will have to use a cleaning agent afterwards to remove the residue these tapes will leave.

The final step in your ‘pre-press’ preparations is to block out any unwanted holes in the emulsion. You can use tape, specialty emulsions, or even specially designed “block-out” pens to seal these holes.

Now you will place your screen over your substrate. Ink is placed over the screen, and a fill bar is used to apply ink to the openings in your mesh. The fill bar always starts at the rear end of the screen, behind a well of ink–the screen is then lifted, so that it does not touch the substrate, and the fill bar is then pulled down carefully. All the mesh openings will then be flooded with ink, and the well of ink is now located on the opposite end of the mesh. Now a squeegee or rubber blade is used to move the mesh down to the substrate below, and the squeegee is then pushed to the rear end of your mesh screen. This deposits wet ink according to your stencil.

Graphic items are usually left to dry between coats of color. When the item is dry, another screen, usually with a different color, is refitted to the item and the process is repeated. You can reuse the same screen after cleaning, or it can be cleaned and used again.