Soft white, 100% cotton, acid-free archival paper (78lb. cardstock).

Format:

- FLAT: 5-1/4” square Flat Card + 5-1/2” square Envelope

- FOLDED: 5-1/4” square Folded Card + 5-1/2” square Envelope

* Square mail requires additional postage. Use USPS Postage Calculator to make sure you are using sufficient postage when mailing.