Squate coup from white air drying clay
Roll out a piece of white air drying clay. To prevent sticking put the clay between two pieces of plastic wrap.
Be careful not to make it too thin at the ends. Cut it in the shape of a square. Use sharp objects to make various pictures on the tile.
When you are ready put the tile in a bowl.
When the clay dries up take it out of the bowl.
At the end you may apply transparent lacquer.