For these inks, there are three destinations:
- For optical reading: printing of small colored boxes inside which a black pattern (number, letter, cross, etc.) is written, manually or by printing. The reader (comprising a specific colored filter) will then only read the inside of the colored boxes (the black pattern), the rest being made invisible by the reader’s filter. There are a large number of optical drives: IBM, SCAN DATA, HONEYWELL BULL, FARRINGTON, CONTROL DATA…
- For scanning: mainly intended for the preparation of “Euro” checks. The background of these checks is printed using inactinic inks, whether fixed, gumable or deleble. Since bank scanners are digital, all that matters is the contrast value of the final print, which must be greater than 60% (apart from the fact that the ink must not contain any trace of black).
- Infra Red Blacks: these are formulated, without carbon black, so as to be completely transparent (therefore invisible) under infrared radiation beyond 700 nanometers. The main use of this type of ink is the masking of secure data such as, for example, certain barcodes.
