Small, with about 11 flutes to the inch. Large, with about 4 flutes to the inch.
Those kept in stock range as high as 30 feet in area, the length not exceeding 120 inches, or the width 36 inches.
Both plain and fluted (large and small) are made in the following thicknesses : - 1/8, 3/16, 1/4, 3/8 inch. The 1/8 thickness weighs about 2 lbs. per square foot, and the other thicknesses in proportion.