Blue coloured Test Inks are special testing liquids in ranges of defined surface tension (in accordance with ISO 8296 / ASTM 2578 / DIN 53364). The surface tension of a substrate is checked by simply applying the
Test Ink to the surface. The blue Test Inks are available in a range from18.4 to 105mN/m.
Test Pens filled with blue Test Ink are available from28 - 70mN/m.