The present invention relates to a powder composition, in particular a fingerprint powder composition for the visualisation of latent fingerprints. Such fingerprint powder compositions comprise carbogenic nanoparticles which, when mixed with a suitable diluent (including any existing or future fingerprint powders), exhibits excitation-dependent emission properties which enable the fingerprint powder compositions and imagable fingerprint impression patterns formed thereform to be imaged in a variety of different colours by simply varying the wavelength(s) of any excitation radiation. As certain backgrounds can render visualisation of fingerprint impression patterns very difficult, having the flexibility to judiciously tune the foreground colour of the fingerprint impression patterns is a significant advantage since it permits instantaneous improvements in visualisation without needing to resort to using a different fingerprint powder. The invention also relates inter alia to corresponding methods and specialised apparatus for fingerprinting.
