"Chabana" comes with minimal rules and appeals to those who prefer a simple, natural look in their creation. The arrangement is a seasonal expression of flowers placed in a simple vase or basket. It is intended to both heighten and deepen the atmosphere of the tea gathering as called for by the occasion. The materials for the vases range from bronze to both glazed and unglazed ceramics as well as bamboo, glass and other materials. An important concept in "chadō" is the distinction between "shin", "gyō", "sō", which may be rendered as "formal, moderate, relaxed", a distinction which informs every aspect of chadō. If the space where the tea gathering is taking place is a formal venue, such as a large "shoin" style reception room, then the "chabana" suitably should be in a formal vase or basket.