LUX #9 Regular Envelopes (3 7/8 x 8 7/8) are commonly used as a reply envelope for invoice and business mailings.
The mail system workhorse, great for personal or corporate business. #9 Envelopes (3-7/8" x 8-7/8") are ideal business reply envelopes. No. 9 envelopes are designed to fit nicely inside the standard #10 envelope. The #10 "Legal" or "Business" size envelope is most common, but there are 14 regular-postage sizes to suit virtually any invoice, sales piece, check or correspondence. printed. All are available with moistenable flaps on the long side, some available in peel and seal. Plain or printed.
#9 Regular Envelopes (3 7/8 x 8 7/8) are commonly used as a reply envelope for invoice/business mailings, sent to recipients inside #10 Envelopes in order to mail something back to the sender