All in Slip
The Nautilus pattern is a very simple process, created by stamping a pattern in thick slip while the piece turns slowly. It is an interesting pattern on its own, but also provides a textured surface for glazes to flow over.
The Drippy Slippy pieces came about from a desire to replicate the glorious drippiness of some glazes, but in the clay itself.
Slip is just another name for liquid clay. You can buy it ready made or mix it from powdered ingredients, but the simplest way to make it is to use the dried clay leftovers from trimming pots. The process really couldn't be much simpler.
