Prior to the explosive handling, and in order to study whether sweat or common exogenous components can influence the Ra- man spectra of handprints, the seven volunteers washed their hands in ultrapure water and left to air dry for 15 min with the aim of regenerating the sweat as proposed by Gilchrist et al. [18]. During this time, participants were not allowed to handle anything to minimise external contamination. Handprints from both hands were then deposited using a light pressure on the adhesive side of a clear self-adhesive vinyl book cover film of 22 38 cm size. For sample conservation and protection, films were covered with an- other piece of film of the same size. Additionally (and with the aim of testing the influence of common dirt), the handprints (right and left) of two participants who had not washed their hands for at least 3h and had performed normal daily tasks were also