Special Blue & Green Crackle 4 inch Kugel, Catalog Number: B1413C-100 Combination colors of cobalt blue, green, and a little red. 4" Diameter. Crackle kugels use 2 layers of hand blown glass to create the ball. One of the layers is crackled with cold water right out of the kiln to create the optic effect. Because crackle kugels are made with 2 layers of glass, they tend to be heavier than our standard design kugels. They are also made with a bit larger loop. Wonderful addition to any collection, please check our inventory for stands, displays and ornament trees to display your ornaments.