What makes this powder unique is that, when illuminated with infrared light at 980 nm, it emits visible light of a shorter wavelength (around 550 nm and 660 nm, perceived as green/yellow‑green light; see the Spectrum tab). This phenomenon is known as anti‑Stokes emission. 

In conventional fluorescent powders, the process works the opposite way: they are excited with shorter‑wavelength light (such as UV or blue) and then emit light with a longer wavelength, known as Stokes fluorescence. 

Many materials—such as colored plastics, printing inks, and paints—naturally fluoresce in the same range as standard fluorescent fingerprint powders, which can reduce the contrast between the developed fingerprint and the background. 

The VISAS powder avoids this issue. There are no known natural materials that exhibit the same anti‑Stokes emission. Because the excitation uses invisible infrared light, the background remains almost completely dark. In a darkened environment, only the fingerprint itself becomes visible or photographable, resulting in very high contrast. 

The powder can be used for dusting fingerprints, but it can also serve as an alternative to cyanoacrylate post‑treatment dyes such as Basic Yellow 40 and Ardrox.