To use the envelope liner: Print the file and cut to size. Insert the liner into a square flap A7 envelope - the bottom of the liner should reach the bottom of the envelope, and the top of the liner should be straight. Fold the flap of the envelope as if you were going to seal it. Then open it and secure the liner onto the envelope with double sided tape or a glue stick.
I chose to use the grey background for our celebration this year. You can see it above framed on my bar cart, and below on the natural colored linen tablecloth. By the way, if you really want to go the extra mile, you can order these vintage harvest stamps from Verde Studio on Etsy.