K2 on paper refers to paper material infused or sprayed with synthetic cannabinoids, laboratory made chemicals designed to mimic some effects of cannabis. These products are sometimes known as “Spice, synthetic weed, or “herbal incense,” although many contain no natural cannabis at all.

Synthetic cannabinoids are often absorbed onto paper or plant material and may be smoked, vaporized, or otherwise consumed. Some products have also appeared in correctional facilities due to the ease of concealing infused paper.