Our ballpoint refills in blue, black, and red colors satisfy all the criteria imposed on document-proof inks.
These criteria include: smudge resistance, erasability, lightfastness, and water resistance. The special ballpoint paste is fast-drying, cannot be modified, and cannot be removed without leaving a trace. The ink also remains legible after a defined period of exposure to sunlight, which means that it cannot fade beyond a certain degree.
If the ink comes into contact with water and runs, the lines of the writing still remain visible. The paste for ballpoint refills 337 and 38 is document-proof under ISO 12757-2.