Make Shrinking Keepsakes

Watch a marker drawing shrink to a third its size in under 3 minutes, then try it yourself.

 

Materials you'll need

• clean type #6 plastic container (look for the recycling symbol with a 6, like a clamshell or deli lid)
• permanent markers
• scissors
• hole punch
• parchment paper
• baking tray
• keyring or lobster clasp

 

Step-by-step tutorial

Step 1: Cut a flat, clean piece from a type #6 plastic container. Check the bottom for the recycling symbol with a 6 inside before you start.

Step 2: Draw and color your design directly onto the plastic with permanent markers, filling the whole shape in.

Step 3: Cut the shape out with scissors, following your outline.

Step 4: Punch a hole near one edge before baking. The plastic can't be punched cleanly once it's hardened, and this hole becomes the loop for your keyring.

Step 5: Set the cutout on a parchment paper–lined baking tray.

Step 6: Bake at 325°F for 1 to 3 minutes. It'll curl and twist first, then flatten back out and shrink to about a third of its original size.

Step 7: Let it cool completely, then loop a keyring or lobster clasp through the hole to turn it into a keychain.

Learn more

This works because of the plastic itself. Type #6 plastic (called polystyrene) is manufactured by heating it, stretching it into a thin sheet, then cooling it fast — kind of like freezing a stretched rubber band in place. When you put your design back in the oven, that heat lets the plastic's long, tangled molecule chains relax back toward their original scrunched-up shape, so the piece shrinks to about a third of its size and gets about nine times thicker. It curls and twists on its way there because different parts of the shape shrink at slightly different moments, then it flattens back out once the whole piece has warmed evenly.

No jump rings or clasps at home? Craft Hardware Set comes with everything kids need to turn shrunk charms into keychains, pins, or bag charms, already sized and ready.