I'm crazy about white slip

I can't remember the name of the white slip I've been using, I think there are several different kinds, but it's really cool. if it's applied thick or uneven it cracks and in the most interesting ways. I love it, it really stands up. I just fell in love with this white clay body, but this slip is making me want to use only dark bodied clays... The first image with slip on it is a vase that I made from 3 pieces all thrown separately, the spout, and the halves of the body, and then I joined them all together. I don't know if it came out all that good or not. It looks a lot like a ring vase I made 2 months ago, which is the top image, and which doesn't have any white slip on it. I think they look very similar, but it wasn't done on purpose. The bottom image is just a small tokuri, or vase.