Heavyweight Blank Greeting Cards Set (40 Cards & Envelopes) 4.25 X 5.5. Blank Greeting Card Paper & Envelopes. (40 of each) Bright White. 80# Premium Smooth Cover stock. 4.25 Cards measure 8.5 x 5.5 when flat. Envelopes measure 4.375 Scored and shipped flat for easy printing. Laser, Inkjet & Copier Compatible.