untreated. There are similar portable tea-making sets called , in which case the box is formed through basket weaving. Charcoal-related items Ash Ash, known as , appears most commonly in in the portable brazier (), the sunken hearth () which may be used in a tea room in the cold season, and the container for the lighter fire in the smoking set (). In tea ceremony, ash serves as a protective bed for the charcoal fire. Great care is given to the quality and appearance of the ash, and there are different kinds of ash for different purposes. They include the following: – used as to decorate the sculpted ash in a brazier. It is a beautiful, smooth white ash produced by burning wisteria bean pods. – a dry ash specially prepared to have a smooth texture free from visible impurities. This is the main kind of ash used in portable braziers. – produced by burning the shells of water caltrops. It is a smooth reddish-brown ash mainly used in the container for the lighter fire in the smoking set. – the slightly damp ash used in the sunken hearth. – sticks of roasted straw. The black is neatly arranged on top of the ash in the brazier. This is reserved for the final days of the brazier season and the use, at that time, of a worn-looking metal brazier (). is also used in hand warmers () and . Ash container is a shallow bowl used by the host to carry the ash into the tea room for the charcoal-laying procedure (). It carries the "sprinkling ash" () for the procedure in the case of a portable brazier (), and the "moist ash" () for the procedure in the case of a sunken hearth (). The styles for these are different. Ash spoon The is a spatula-like implement mainly used to shape the ash in the portable brazier (), or to sprinkle ash during the charcoal-laying procedure. Charcoal refers to the charcoal used in . for the most part is made of chestnut-leaved oak (), carbonized by long hours of smoldering in a kiln. The long pieces of finished charcoal are cut into specific lengths for use; the lengths differing depending upon whether the charcoal will be used in a brazier or sunken hearth. In addition, a unique kind of charcoal called is used in for its artistic effect.