Preheat oven to 400 degrees F.
Stack the slices of American cheese and cut it into 16 small squares. Separate the pieces, and transfer them to a small bowl. Add the salt, chili powder, and garlic powder toss to combine. Arrange the 32 cheese pieces in 4 rows of 8, on a parchment paper-lined baking sheet, leaving as much space in between each as possible.
Stack the Colby-Jack slices and cut them into about 24 small pieces. Arrange them on another parchment paper-lined baking sheet in 4 rows of 6¿without any seasonings.
Bake both until well-browned and crispy, about 7 and 7 1/2 minutes. If undercooked, they'll be soggy, so don't be afraid to check them and put them back in for more time, if needed.
Cool the crisps and crackers completely before serving¿as they cool, they'll crisp up. Store on the counter in an airtight container for a few days.