Liquid K2, a form of synthetic marijuana that causes erratic conduct when smoked, is currently being smuggled to inmates from the mail, sprayed on letters and pages of textbooks. This way of K2 is way more difficult to detect than common leafy K2 products which look far more like cannabis. https://bookmarkfame.com/story16990107/an-unbiased-view-of-k2-spray-on-paper