Our clear document binding covers are pre-punched with 19 rectangular holes along the binding edge with the perfect spacing for plastic comb binding spines and spiral-o twin loop wires. Comb-punched clear covers are available in three different thicknesses: 5 mil lightweight, 7 mil medium weight, and 10 mil heavy weight. Clear presentation covers are also often called clear acetate covers. They are stocked in several popular sizes, including letter size 8 ½" x 11" and several over-sized options such as 8 ¾" x 11 ¼", 9" x 11", and 9 ¼" x 11 ¼".