Answers to frequently-asked questions
Not only are there a whole range of durometers, but also a chocolate-box of profiles (the shapes of the actual printing edges). Textile printers tend to stick with the straight and bullnose blades, selecting profiles depending on the mesh count and the desired thickness of the ink deposit . (Fancier beveled configurations are usually used on smooth glass and ceramic substrates.)
Straight-edge squeegees are the most popular among textile screen printers. A true 90° angle, straight-edged squeegee is used with mesh counts of 230 threads/in. or higher. However, sometimes the knuckles of the mesh will cause excessive vibrations with a sharp edge as it rises and drops into each valley of the mesh. This undesirable washboarding can be eliminated by skewing the angle of the squeegee path slightly, so that the right side of the squeegee leads its left side slightly.
Another solution to the bouncing is to blunt the sharp edge of the squeegee. You can gently dull the edge with very fine sandpaper, using straight, even strokes across the entire length of the blade.
Your dull-edged squeegees-whether by sanding or natural mesh abrasion--are compatible with mesh counts of 100-200 threads/in.
For puff or glitter ink, or a white printer, mesh counts coarser than 96 threads/in. dictate the use of a bullnose profile. Such a rounded profile mashes the ink into the mesh and provides a thicker deposit on the substrate. Of course, low mesh counts, thick ink deposits, and rounded squeegees preclude fine-detailed designs.
What Kind of Squeegee Edge Do I Need?
For those fine details found in high-quality production runs, especially on automatic presses, not only must your squeegee edge be sharp, but also free of nicks, waves, and varying blade height. A tiny smidgen nicked out of a straight edge can translate into nasty streaks, especially noticeable in large areas of a single-color design printed with transparent inks.
Waves in the printing edge might be due to compression of the holder screws, swelling from chemical action, or incorrect squeegee storage. These waves will blight your printing with poor coverage (or even a color shift) due to uneven ink deposit where the squeegee is unable to "kiss" the mesh and clear the screen.
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