Use the included test card to apply your primer, paint and clear coat to test the color before applying it to your car. The test card has multiple test squares that you can use, and each area on the test card is at the perimeter of the card, so we recommend that you apply your test right up to the edge of the card. That way, when it is dry, you can hold it next to your car and have a seamless edge between the test color and your car color.