The name "Kawara" originally refers to a clay tile, and in Germany, for example, a tile made of clay is called Ziegel (tile) to distinguish it from the other tiles made of different materials.
瓦は本来粘土瓦を指し、例えばドイツでは粘土製のものをほかのものと区別してZiegel（ツィーゲル＝瓦、煉瓦）と呼んでいる。