ASSEMBLE THE WINGS: With scissors, cut off the top and bottom of your 2-liter bottle, then cut the remainder lengthwise into quarters, making four identical wing halves. Arrange two halves with the long, flat sides next to each other, one curving up, the other down. Leaving a ¼-inch gap between the two, staple their ends between ½-inch-wide strips of 3/32-inch plywood. Drill a 1/8-inch hole through the edges of the plywood strips in the center of the gap. Repeat for the second wing. Paint each wing black on one side; half black, half white on the other.