The small particles bind on the fatty/oily parts from the fingerprint residues due to the addition of the surfactant; This can be only feasible as a result of relative steadiness of such factors maintained after some time. Therefore, aged fingerprints could be produced by using the small particle reagent approach. https://thomasl863dbx7.blogars.com/26434569/hodgdon-varget-smokeless-gun-powder-fundamentals-explained