White A-6 announcement envelopes are a particular style of announcement envelope with a deep square flap and double side seam construction most commonly used with baronial cards for informal mailings, social, and commercial announcements. A-6 envelopes measure 4-3/4" x 6-1/2" in size, and some are machine insertable envelopes. A-6 announcement envelopes are perfect for that formal look when sending invitations or R.S.V.P. cards. There are also foil-lined A-6 announcement envelopes for an added touch of elegance. The Envelope Supplies Shop also offers the panel cards that would fit these envelopes.