This past summer, I took a class on pit firing at the Kirkland Arts Center. Pit firing is simply a technique where pots are placed in a pit and certain materials are put around them and burned. Fume marks are left on the pots that depend on the materials in the fire and their proximity to the pots. One example of a pit fired pot is in the logo in the upper left. For more, gaze into the fire (i.e. click on it).