Heat oven to 275°F with racks in upper and lower thirds. Line rimmed sheet pans with parchment or nonstick foil. Cut out and discard stems and center ribs from kale. Aim for 32 cups of leaves (use a 1- or 2-quart glass measure and pack leaves without crushing them)....

Heat oven to 275°F with racks in upper and lower thirds. Line rimmed sheet pans with parchment or nonstick foil. Cut out and discard stems and center ribs from kale. Aim for 32 cups of leaves (use a 1- or 2-quart glass measure and pack leaves without crushing them). Wash leaves and dry well. Once the first half is in the oven, repeat