Envelopes that will fit your 4x6 inch cards like a glove. These A4 envelopes are perfectly sized at 4.25 x 6.25 to hold any 4x6 enclosure.
Totally Tiffany - Stamp Pocket and 5 x 7 Magnetic Sheet Inserts Bundle
LUXPaper A4 Invitation Envelopes
Bulk Blank White or Natural 4x6 inch Discount Card Stock
Envelopes - Fine Cardstock
10 A8 Envelopes Euro Flap Pink BULK DISCOUNT AVAILABLE
Paper 101 - How To Cut Flat and Folded Cards – Cardstock Warehouse
A4 Envelope Digital Template Bundle for 4x6 Cards, Wedding and
Blank Cougar 4x6 Folded Cards 50 Pack for Card Making and DIY
Blank Cards By Size - A1, A2, A7, A9 & Other Standard Size Cards
Basic Colored 4x6 Folded Card Stock Note Cards
A4 Envelopes for 4x6 cards - CutCardStock
Cardstock Warehouse, Invitation & Scrapbook Paper