Springhill Colors Index Card Stock - 250 sheetsSpringhill Index weight card stock paper A durable hard surface for exceptional ink hold out. The 90lb index meets 7 pt caliper for return card postal regulations minimum, for cards of not less than 3. 5" x 5". Please note that index weight is lighter than cover weight. 90# Index = 163 gms = approximately 65# Cover 110# Index = 199 gsm = approximately 80# Cover Uses: Brochures, covers, file folders, tab divider pages, table tents, flyers, post cards