Has anyone here ever done this experiment? A buddy of mine and I were thinking of setting this up but we had a few questions first. Is it better to use pure isopropyl or pure ethyl alcohol? I have read both from different sources. To conduct this more than once, do you just have to replace the dry ice and alcohol? What is the best way to photograph the trails? How do you recognize which particles are forming each trail? Hope I posted this in the right section. If not, feel free to move it. Thanks for all the help.