Lumina Polymer Air Dry Clay. Lumina Clay is an air-dry polymer resin clay that does not require heat to cure. When dried Lumina clay is waterproof, extremely durable, has a high flexibility, is acid-free and is translucent. It is great for rubber-stamping, figurines, making flowers, ornaments, jewelry and so much more. This package contains (1) 5.25oz/150g block. Clay conforms to ASTM D4236.