The 40 green spray paints were bought in paint shops in the Lausanne region, Switzerland. The characteristics of these paints are described in Appendix 1. Eleven of the samples were automotive paints (A), while the other 29 were for household use (H). In fact, the manufacturer's information indicates that these latter are for indoor and outdoor use, for decoration purposes and for different types of surface e.g., wood, metal, plastics, polystyrene, etc. The samples were prepared by spraying the paints on microscopic glass slides from a distance of about 30 cm. The samples were left to dry for 24 hours at room temperature. For each paint, a shaken and an unshaken sample were prepared. For unshaken samples, the cans were left standing for 24 hours. For shaken samples, the cans were shaken manually for 45 seconds. The manufacturer's instructions mentioned a shaking time of about 2-3 minutes, nevertheless, it was considered that this long shaking time is seldom respected by vandals committing a crime.