This new family of inks can be printed by offset, letterpress, silk-screen, flexography and gravure and is used in high security documents. Once printed inks are totally invisible, and will react to a Infra-Red laser by a visible colour emission.

The reaction will be the following: under the excitation wavenlengh of 980nm (infra-red), the emission will occur either in blue at 470nm, or in green at 545nm or in red at 660nm.

The strongest emission will be in green, whilst the red and blue emissions are weaker.

Petrel can deliver Infra-red Lasers with this excitation wavenlengh at 980nm.