Astrobrights Blast-off Blue Envelopes - A7 (5 1/4 X 7 1/4) 60 Lb Text (25 Per Pack) Astrobrights Blast-Off Blue Envelopes - Size A7 (5 1/4 X 7 1/4) 25 Per Pack. Square Flap - Regular Gummed Recommended Applications - Greetings - Invitations - Announcements Holiday Cards - Photographs Side Seams - - Open Side FSC Certified - Manufactured Acid Free