A roach refers to the end of a joint that often gets discarded at the end of a sesh. Now depending on if you roll your joints with a filter or not will affect how much cannabis is left in the roach. Rolling with a filter usually has less cannabis left over at the end. As an attempt to finish every last bit of bud rolled up, there are two main techniques. First being the “Roach Clip” of the 60’s, its used to hold your joint as you puckerup to the last few tokes. The other commonly known idea for saving your roaches is collecting them and re-rolling these roaches into a joint of their own. This is a messy process but fans love the potent joints created from the build up of resin that’s collected.