I have been using Phytowax container with no additives. (other than fragrance and liq dye) Making many samples, trying different fragrances and all of them look great, burn great, and making great progress. And then....when the orders start rolling in and the products need to be finished quickly.....they are all showing up with cracks! I have tried different boxes (lots) warming up jars (even warmer) pouring at all different temp and still getting cracks! The cracks are appearing along the side of the containers and across the top of the finished product! I began using veg stearic about 3-5% (still playing with the %) and seems to be alittle better.