These A1 Clear Plastic Envelopes fit note cards, thank you cards, and much more. The envelopes are designed to fit a single card and envelope, but can accompany up to 2 cards and envelopes. Clear Plastic Envelope bags can be used as a package for your cards or as a protective sleeve. Whichever way you use these plastic envelopes, they do the job! A1 Clear Plastic Envelopes measure 5 5/8" x 3 9/16" when sealed. These envelopes are made to fit cards of size 4 7/8" x 3 1/2". Each Clear Plastic Envelope Sleeve features an adhesive to seal the envelope. 100 A1 Plastic Sleeves.