A fit for the popular A2 4x5 invitation card, A2 4 3/8 x 5 3/4 envelopes are the most common invitation envelope size, also great for sending announcements, invitations, small booklets, brochures, greeting cards, photos, baby shower invites and distinctive business stationery. Endoc Starburst envelopes are a mid price collection of colored envelopes . Made in the USA of smooth papers. SECURE GUMMED SEAL: Every single envelope comes with a traditional gummed seal. The moisture activate gummed flaps not only makes sealing these colored envelopes easy, but they provide a secure hold.