Dyne pen is used to identify surface energy of a material, usually plastic or film. The Unit of surface energy is Dyne.
Dyne pen are filled with an ink which has a particular Dyne value. This value is mentioned on the pen. Ex:34,36,40 etc. When we apply the ink on a surface with higher Dyne value, we have an uniform application. If it is lower we have non uniform rippled like effect. This effect occurs immediately or after few seconds.