For a dramatic effect TRIANGULAR COPA : The last tool you might want to own but it looks great in the tool box. With a little practice you can be a pro, make sure your assistant practices too. The triangular copa will make crisp triangular wraps that will vary in size with the amount of glass applied. Augustine Frisnel found that triangular wraps (prisms) have great optical properties check him out. Similar to the large, but with a shorter working blade. Ideal for smaller pieces and smaller hands. 8'' blade.