Dyne Pens and Test Fluids

Dyne testing pens and dyne test fluids (or inks) offer a quick and easy way of measuring surface wetting or surface energy. When the test fluid is applied to a substrate, the fluid will either form a continuous film on the surface or pull back into small droplets.

If the fluid forms a continuous film which is stable for three seconds, it indicates that the surface energy of the substrate is at least as high as the fluid value, measured in mJ/m², mN/m, or dyne/cm – often known as “Dynes”.

If you apply a 38 Dyne Pen to a substrate, and the fluid stays as a film for three seconds, the substrate has a surface energy of at least 38 dyne/cm. By using a range of pens or inks of various dyne levels, the surface energy of a substrate can be determined to a narrow range.