Numbering inks are mainly used by letterpress for the numbering of various security documents. Consequently their viscosity is suitable for this type of printing process.
They all have a verygood light fastnes of 7 on the blue wool scale.
In addition to their visible colours, they can be:
– fluorescent in green, yellow, or red
– migranting in red or pink
– they can be used on papers of 90gsm maximum, but not a coated paper, nor on plastic, nor on metallised supports.