Crater Lake Midfire Glaze
Glossy 
Crackle 
Use Thick 
Food Safe 
Reactive 
Might be runny 
Here is an image of Crater Lake Crackle glaze applied two shards (white and buff) fired to 1200C. The dramatic difference in effect reinforces the importance for potters to test materials in their own particular circumstances, rather than rely on generalised advice from suppliers.