Crackle glass , sometimes called ice glass , has an uneven surface resembling cracked ice that has partly remelted. It is made by dipping the molten glass item into cold water for just a moment, and then reheating and blowing it to widen the cracks.
Overshot glass is different, although it is often confused with crackle glass.
Here are some books on crackle glass that you may find helpful. Click on any book cover on this page to read more about a particular book, including price and any available discounts for buying on-line. Angela M. Bowey, 1998.