Our fingerprint kit came in the mail last week. It included a thermometer and a pair of plastic tweezers, both marked "Please return." There were two little envelopes containing four black strips of some kind of substance that apparently got malleable when heated. There was also a sample strip of someone else's fingerprint. Finally, the kit contained a set of very thorough instructions with frequent use of caps lock to emphasize such things as "DO NOT BURN YOURSELF." All of this, plus some business cards and advertising postcards, in one priority mail flat rate envelope.
But he had work to do now. We read the instructions completely before starting, as we were admonished to do in the second step. First, we set sixteen ounces of water on the stove to boil. While that was going on, we soaked our hands in warm water. According to the information, this would cause the ridges on our fingers to become more pronounced.