Spirulina, a substance extracted from naturally occurring algae, is non-toxic and fluoresces brightly in the infrared and once ground to a fine powder, is ideal for dusting fingerprints.
Most luminescent powders emit visible fluorescence which may not stand out brightly enough against ‘busy’ background, or worse still, ones that fluoresces at the same wavelength as the powder.
Spirulina has the useful property of fluorescing intensely in the infrared, so that previously troublesome backgrounds can often be seen to ‘drop out’ completely, revealing high contrast prints with excellent ridge detail.
A significant application is the imaging of prints on the new style plastic based banknotes, as well as on metals, glossy paper and plastics in general.
