Announcement envelopes that will easily fit folded or flat cards that measure 4.5" x 6.25" and 4x6 inch cards are known as A6 envelopes (also known as 6 Bar envelopes), and they measure 4.75" x 6.50". These discount envelopes are great for enclosing your save the dates, DIY invitations, thank you cards, graduation announcements, and greeting cards. From Brown Bag to Metallic Envelopes to Linen Envelopes, CutCardStock has the envelopes you need.