The exact mechanism for development of marks using powder
suspensions is unknown, and studies by CAST to establish which factors
are most important are continuing. However, it is thought that the
development process is very similar to that for small particle reagent,
where the micelles are formed around the particles by the surfactant.
Some component or property of the latent fingerprint destabilises these
micelles, causing the particulates to deposit preferentially on the
fingerprint ridges.