Letter size copy paper Basic weight: 70 ,75 ,80g/m2, Size : 70 ,75,80GSM 8.5*11,A4,8.5*13,A3,11*17, and foolscap paper sheet is 17 x 13.5inches (432x343 mm) . Moisture 3.5%-4.5%, Whiteness: >98% Thickness: 103-110 um Surface roughness TS ml/min: 75-175 Surface roughness BS ml/min: 100-200 Bending stiffness MD: >110 Mn Bending stiffness CD: >50 Mn Opacity: >94% Brightness: 101-104% CIE whiteness: 148-15 Cobb Test: 27-33 g/m2 27-33