Roaches don’t filter the smoke but they do allow it to flow, and smoke condenses in cylinders. A good roach also stops the joint from dissolving in your mouth or burning your lips when you chase that last elusive toke.
Here’s how to make a good one.

The shape and size of roach is down to personal taste. Wide roaches can make smoke rough whereas tight ones tend to clog, so somewhere in the middle is probably best.

Plain, unprinted card is healthier as some printing inks can emit poisonous fumes when burnt. An excellent roach can be made from a 2cm by 7cm strip of thin card. Tightly roll the card at a slight angel so that the end of the roach is conical. Roll your joint with the roach already inside (conical end facing outward) and let the card spring out a little to allow the smoke to flow.

Some smoker prefer to insert the roach after making the joint (I do), Others find that putting the roach in before rolling is less fiddly and makes for a neater fit and a speedier roll. Go with what suits you.Check out the joint pages for some roaches that do more than just act as mouthpieces.