This clear glaze with a little iron oxide, on a white clay body, is simple and amazing. Fired in an electric kiln to about 1100C, oxidizing atmosphere. The glaze is slightly runny and tends to flow into creases and hollows where it is thicker and therefore darker.

The left tile's 'negative' design was carved into a thick square of plaster of paris. White clay was then pressed carefully into the negative. After a short time the positive will release. The negative must be bone dry before the next 'print' is made.

The right tile was a softish thick flat slab of white clay to begin with. Using found beach shells, stones, seaweed etc, these are carefully arranged on the clay slab and very lightly pressed into the damp sticky clay surface. Keep in an air-tight container until your design is done. A water spray mister is handy.

Surround the tile with a 4-sided box roughly twice the depth of the tile master and carefully pour plaster to the height of the box walls, avoiding air bubbles. Some gentle banging on the tile-making table with a wooden or rubber hammer will cause any air bubbles to rise away from the surface. Let the plaster master dry thoroughly.

It's quite ok to press the white tile clay into the mold in marble-sized lumps, rather than a thick sheet. Fewer air bubbles.