Reddit reviews Columbian Invitation Envelopes, A2, 4-3/8 x 5-3/4 Inches, White, 100 Per Box (CO198)
We found 1 Reddit comments about Columbian Invitation Envelopes, A2, 4-3/8 x 5-3/4 Inches, White, 100 Per Box (CO198). Here are the top ones, ranked by their Reddit score.
Envelope is designed for computer generated invitations, greeting cards, announcements and more. Sized to hold a 8-1/2" x 11" sheet folded in quarters.Premium 24lb white wove stock.Executive Style diagonal seam V-flap construction. Moisture activated gummed seal.4-3/8" x 5-3/4"100 envelopes
I think these are the size you're looking for.
EDIT: These are also at a really good price, for right now at least.