Glue

• 1). Clean the surface of the metal and the hardened polymer clay object with an all-purpose cleaner. Wipe the metal with a cloth until it is completely dry. Wipe both clean surfaces with rubbing alcohol. Wait for the alcohol to evaporate.
  
  
• 2). Scratch the surface of the metal with a nail file in the location where you plan to apply the polymer clay. Scratch the section of the polymer clay object with the same file in the area to fit onto the metal. The scratches help the adhesive adhere to the slick surfaces.
  
  
• 3). Spread one-part epoxy jeweler's glue onto the scratched surface of the metal and the clay. Wait one minute.
  
  
• 4). Press the hardened clay, glue side down, onto the gluey section of the metal. Apply pressure to hold the clay in place on the metal for at least one minute. Allow the glue to dry between 24 and 72 hours.
  
  

Bake

• 1). Clean a metal surface, such as a pin back, with all-purpose cleaner, followed by rubbing alcohol.
  
  
• 2). Place a soft or hardened polymer clay object onto a baking sheet covered with tin foil. Apply a line or dot of liquid polymer clay onto the clay object wherever you plan to place the metal.
  
  
• 3). Press the metal onto the liquid clay. If you'd like to camouflage the metal, such as a jewelry pin back or flat back bail, apply liquid clay to the clay object around the metal. Cover the portion of the metal with a thin layer of soft polymer clay. Press the soft clay into the liquid clay.
  
  
• 4). Place the baking sheet into a baking bag to protect a regular household oven from polymer residue. Bake the clay and metal according to the clay manufacturer's directions. Allow the clay and metal object to cool completely.