So what’s the big deal about having screens with proper tension? There are two issues that may occur when you use screens with too soft mesh. These are (1) fabric wave, and (2) mesh release.
Fabric wave means, as you apply pressure and pull or push the squeegee across the screen and shirt, a small wave of screen mesh may form in front of the squeegee blade. On the bottom side of the screen, this wave of fabric may fill with ink as it passes over the image, and then smear ink onto the garment when the squeegee reaches the edge of the graphic.
The more common issue is mesh release. We print garments off-contact. This means the only place the screen physically comes into contact with the garment is along the sharp edge of the squeegee blade. If your screen mesh is too soft, the mesh will not release from the garment as you pull or push the squeegee across the image. When the mesh does release, often when you lift the screen, the ink on the shirt will try to hold onto the screen mesh, causing a rough finish to your print.
On a multi-color job, soft mesh will stick to the previous colors on the shirt, and the ink picked up will begin to build up on the backs of your subsequent screens. In short order, your prints will start to appear muddy around the edges and where colors touch within your image.
When printing dark garments, poor screen tension can be doubly troublesome. The ink from the white underbase print is pulled up with the screen, and then flash cured into that position. My best analogy is seeing a thousand little mountain peaks standing up on the shirt. Under a microscope, the surface would look like the Alps. When colors are printed on top, the print feels very rough, or worse, hundreds of tiny white specks show throughout the print area where the white underbase peeks through the colors.
When you call me and say, “There’s something wrong with my ink! I see a thousand white speckles….” It’s not the ink. It’s almost never the ink. It’s your screen mesh tension.
To recap, when a print feels rough, it is usually caused by a screen with poor tension. A tight screen will give you a crisp, sharp image. And on a manual press, a tight screen will cause far less printing fatigue during the process. Screen printing… it’s all about the screen. Write that down.