PA Paper Accents cards and envelopes are acid free, lignin free, buffered and archival quality. The cards and envelopes are made from heavy cardstock. Decorate with rubber stamps, rub-ons, stickers and much more. What could be more fun then decorating and personalizing your cards and envelopes! Details: Black4.25" x 5.5" (A2) card size 4.38" x 5.75" envelope size 80 lb/216 gsm 25 sets Heavyweight Acid and lignin-free Buffered and archival quality