Quicktest 38® serves to check if the treatment of polyolefins (polypropylene, polyethylene, polybutylene) has shown an effect onto the material. A stroke of the pen leaves a full line on the material if the material's surface tension has a value of 38 mN/m or more. If the material's surface tension is below 38 mN/m, the fluid contained in the pen will form small drops on the surface. The fluid applied to the surface will dry within seconds, it does not need to be wiped off anymore.