You might know this scenario: press is all set up, registration is perfect, shirts are unboxed and ready to become someones favorite piece of apparel. Then the printing starts and your design isn’t turning out how it should. It’s frustrating, and unfortunately, very common.
Although there are a variety of reason for this, we all know that the stencil we create is the most important medium to our craft as screen printers. And that stencil is created by properly coating your screen. In this article, I will articulate some tried and true techniques for properly coating your screens, in the hope that you will save time and stress in the shop.
First, when coating a screen (whether manually or with an automatic coater) you want to use the rounded edge of your scoop coater. The round edge gives you the proper coat of emulsion and allows you to build your stencil to the proper thickness or EOM (emulsion over mesh), whereas the sharp side of the coater can scrape off the emulsion, or create uneven application.
To coat a screen you will want to start with the bottom of the screen, on the side that makes contact with the garment (also known as the print side). After you fill the scoop coater with emulsion, you are going to line up the coater with the bottom of the screen where the mesh meets the frame. Apply two coats starting at the bottom and working your way to the top of the screen. If you are applying the emulsion manually, turn the screen around and repeat on the inside of the screen (or the squeegee side). This technique allows for proper emulsion thickness on the print side of the screen.
You then want to dry the screen print side down on a drying rack in a humidity controlled room or drying cabinet. Drying print side down allows for the emulsion to flow through and stabilize on the print side of the screen ensuring proper stencil thickness.
Using an Stencil Thickness Gauge will help you determine the thickness of your screen coating and how even it is across the screen. It is a good investment to make if you coat many screens on a regular basis and want to ensure quality control in your shop.
Keep in mind that the type of screen you are using (more specifically the mesh count) will determine how many coats of emulsion that you need to apply. Lower mesh count screens may require more coats than higher mesh counts, but this is ultimately determined by how thick of a stencil you need to achieve your desired ink thickness, as well as the amount of detail in your design.
Proper screen coating doesn’t just avoid headaches and troubleshooting (although it most certainly does that), but it also leads to better ink lay down and coverage, ultimately giving you a better print. By giving your screens a solid stencil and even coating, you print will require less print strokes and faster flash times. This is especially true when printing an under base.
Keep these simple tips in mind when coating your screens, and you will see more successful results!