Here are some instructions on heat embossing on polymer clay. This video includes tips for embossing both baked and unbaked clay. You will need polymer clay, a rubber stamp, pigment ink, embossing powder and a heat gun. Roll out the clay onto a nice thin sheet of clay and bake the selected piece. Then stamp the baked clay with ink as desired. Sprinkle the embossment powder onto the stamped area, and tap off the excess powder. Next, heat the embossed area with the embossment gun and watch the powder change from powder to solid.
You can also add decorative clay borders and bake the polymer clay again to add some flourishes.
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