I came across this DIY Clay Stamped Bowls on Pinterest, and its by the awesome Gathering Beauty
1. Take your air dry clay and knead until soft. Roll your clay out to about 5mm thick.
2. Ink up your stamp and press firmly onto the clay. Repeat until you have covered the clay with your stamped design. Try not to press too hard as you want to be able to lift the clay away from the table easily and not stretch out the design.
3. Take your bowl and place it upside down on your clay. Use your knife to cut around the edge of the bowl. Peel away the remaining clay to leave the circle of clay behind that will form your bowl.
4. Lift your clay circle carefully and place it inside your bowl. Using your thumbs press the clay down gently into the bowl. It works best if you try and apply even pressure as you work your way around the bowl. Where pressed too hard the clay bunched up and creased and the pattern became warped.
5. Repeat until you have as many bowls as required and leave to dry overnight. By the next day the printed side of the clay should be hard enough for you to remove it from the bowl. You may find the clay is still damp where it’s been touching the glass bowl. Place your bowls upside down on a baking cooler rack to allow both sides to dry fully.
6. When your bowls are dry, sand away any rough edges.