Serinity sew on crystals Cosmic (3265) in Jet UNFOILED are loose flat backed crystals that come with a thread hole, enabling the crystals to be sewn onto fabric. Serinity Cosmic shaped crystals feature a rectangular shape with a raised centre that creates a 3D effect. The crystal surface is intricately cut with multiple facets, resulting in a dazzling sparkle. The cosmic shape is designed to resemble a cosmic explosion or a small galaxy, making it a distinctive and captivating element in any design.