Once flat, remove them from the oven. If they are slightly curled, press them with a flat object like a cup or heavy book while they are still warm. 4. Finishing Touches
Use permanent markers, colored pencils, or acrylic markers. Avoid wax-based crayons or pastels, as they will melt in the oven.
You can use #6 plastic takeout containers (polystyrene) as a cost-effective substitute. 2. Design and Preparation
The process takes about 2–3 minutes . The plastic will curl dramatically before flattening out—this is normal.