Raku pottery is so hot when it comes out of the kiln that it causes paper to go up in a flash fire until choked off by the lack of oxygen. Combustion is necessary for the pieces to be smoked properly.
Combustible materials are usually fairly small pieces; this helps to ignite the largest amount of material possible. Another consideration is that material that is nestled against the pot's surface will leave the greatest smoking mark. Such materials include: shredded paper, sawdust, straw, hay, dry leaves, seaweed, shredded cloth, nutshells, and so on.
Hot pots are placed in a chamber with combustible materials. A nest is created out of the combustible materials inside the bottom of the chamber. Extra material should be ready at hand to place inside and on top of the pot. Place the pot in the nest and pull the extra material around it.
The heat of the pot itself will set the combustible material alight. Once active flame has been established, the chamber is closed and the pot allowed to smoke for fifteen to thirty minutes, depending on the effects desired by the potter. Once the flame is well established, close the chamber.
Image courtesy of Lori Buff of Future Relics Gallery.