#10 Foil Lined Invitation Envelopes 4 1/8" x 9 1/2" (4.125 x 9.5 inches) are an elegant spin on a traditional envelope. The grooved, red foil-lining and 60lb. weight make these envelopes special and perfect for mailing letterhead, personal letters, direct mail pieces, and unique invitations. Seal by convenient adhesive strip along square flap. Click the yellow “Add to Cart” button now!