@laughingman,LSD is not the safest because it is small in physical size, it is the safest because the substance is an extremely small quantity and that quantity produces nanogram, and single digit ng at that, amounts of odor particles.And no, I do not think it is obvious what is what. The common sense methodology used by most people is often misguided. Did you know that dogs detect Cocaine much more easily than Weed? Cocaine has more of an odor than Weed, but we smell differently to electronic drug detectors and dogs, which creates a false impression.@OP, there is a pdf (search for "[intel]" tag on forums) on here which describes the majority of popular drugs and their odor residues. In particular, one of the most valuable results was that you should be using HDPP plastic for vacuum packing, it makes a huge difference. The thread was called "geographical profiling tech" and the post with the link is by fizzy.Also, the procedure used while packaging is very important too. There's another thread out there on this, but I forget the name of it.