In order for your glue to work properly, it needs to be able to penetrate (or "wet") your substrate. Some substrates are more impenetrable than others. This is a result of the change in surface energy.
If you would like to purchase a dyne pen and test it in your own facility, here are a few steps on how to take a dyne level test:
Make sure your Dyne pens are not contaminated or out of date.
Make sure your Dyne pens are stored at room temperature.
Before testing, make sure the substrate is clean and undamaged.
Remove the cap and make sure the nib is soaked.
With light pressure, draw three parallel lines on the test area of the substrate with a dyne pen. Disregard your first and second readings, as the nib may be contaminated with old solution. These lines will clear the pen. Only the readings of the third row are evaluated.
Note the time between when the solution is applied to the substrate and when the solution beaded or began to shrink (stay wet). If the solution does not bead up after 3 seconds, repeat the test with the next highest dyne pen. If the solution breaks down into droplets within 3 seconds, repeat the test with the next lowest dyne pen. If the ink holds for one to three seconds before losing its integrity, the marked dyne level is very close to that of the sample.
