What is the size of the flap on a #6 3/4 Remittance Envelope?
The size of the flap on a #6 3/4 Remittance is 3 3/8" x 6 1/2" , or 3.375" x 6.5" . The back flap is 1/4" shorter than the front of the envelope.
Attached are templates of both the front and the back of a 6 3/4 Remittance.