Extra Thick 100lb Cover White Cardstock - 50 Sheets Extra Thick Cardstock perfect for invitations, post cards, covers, and more Made from 100lb Cover (270 gsm) Stock Works on Inkjet & Laser Printers (Copiers too) Measures Letter Size 8 1/2" x 11" NOTE: This stock is very thick. Please consult your printer manual before ordering to make sure it can handle 100lb Cover (270 gsm) cardstock