Kosta Boda Crackle Circular BowlCrackle and thunder a magical wonder! At Kosta Boda, we marvel at beautifully preserved cracks in glass. The bowl in circular glass from the Crackle collection has an expressive, sculptural exterior created using an old handicraft technique where the hot glass is dipped in ice cold water. The circular glass that Crackle Circular is made of, makes the products shift in color, and the small bubbles created during the process of making circular glass