Step 1: What you will need:
- Polystyrene plastic (#6 plastic or PS )* -it is the clear plastic often used in takeout containers (not the foam).
- Metal hoop to attach tag to collar
- Parchment paper
- Coloured markers and a black fine tip marker
- Hole punch
- Toaster oven and oven mitts
Step 2: Determine shrinkage
To determine the amount of shrinkage cut a small piece of the plastic, measure it (length and width), shrink it in oven (see Step 3) and then measure the end product.
Step 3: Shrinking the polystyrene in the oven
- Put the plastic onto a piece of parchment paper and place into a toaster oven (use with good ventilation -eg. with kitchen fan on, open a window).
- Set the oven to 250 F (121C), and watch, first the plastic starts to curl, then it uncurls, then it shrinks .
- The time it takes can vary, but once it uncurls and stops doing anything interesting, it is done.
- With an oven mitt take out the parchment paper, if the plastic is still a bit curled, place something heavy on top, such as a phone book to straighten it out before it cools.