I got this idea from a Pinterest post. You make a block out of clay, about 1-inch square and carve designs into each side once leather hard. Carving out a design makes a relief (raised) pattern as I did on the ones shown here, once you press them into the clay. You can also carve away areas and leave a relief design which will emboss (or recess) the pattern. I use the stamps as a decorative tool on both hand built and wheel thrown pieces.