Empty Petri Dish
1. Place the lid of the Petri dish over the bottom of another dish and mark a straight line on the lid with permanent marker where the bottom of the label is desired.
2. Hold the tip of a teasing needle over a Bunsen burner until hot, then carefully cut along the drawn line on the Petri dish lid. Repeat this step until lid is completely cut.
3. This will not produce a straight line. Sanding or grinding the uneven edge is a useful method in producing the desired edge for even label placement.
4. Place the cut Petri dish lid over the bottom of another Petri dish to ensure that measurements are correct.