Lightly oil a nonstick baking sheet, or cover a regular baking sheet with silicone-finished parchment or a silicone liner. Mound thinly shredded parmesan cheese on the pan, using 2 tablespoons per cracker. Place the portions at least 6 inches apart, then spread each mound into a 5- to 6-inch round with your fingertips.
Bake in a 375° oven until cheese is pale golden brown and melded together, 3 to 4 minutes. Watch carefully - cheese tastes scorched if overbaked.
While crackers are hot and flexible, lift from pan 1 at a time with a wide spatula and drape over a rolling pin (or a room-temperature wine bottle) until cool and rigid. Then use or package airtight at once. (If making crackers ahead, refrigerate up to 6 days.)
Note: To get a lacy look, the cheese must be freshly shredded (the longer the shreds, the better) so it sticks together.
Nutritional analysis per cracker.