Ilysa Bierer and Kira Slye with Polymer Clay TV demonstrate how to make polymer clay business card holders. You can work cabochons into polymer clay to create business card holders. Stamp on clay and use clay with inclusions in it for a different look. First, get a plain business card case and work the clay over it. Add pigment inks, textured stamps and canes to dress up your business card holder. The clay can be baked right onto the metal and will adhere to it. Polymer clay adheres better to metal than it does to glass. For extra adherence, glue the clay to the metal holder before you fire it.