The standard range of Trodat stamp inks (black, blue,red, green and violet) is indelible in accordance with DIN ISO 14145-2 and therefore ensures perfect imprint quality. In addition, the ink colour black fulfills crucial permanence and durability properties according to the DIN ISO 11798 Archivability Standard such as colour intensity (optical density) and appearance of the typefaces, lightfastness, water resistance, abrasion resistance, heat resistance and influence of the printed lettering on paper strength.