https://www.cutoutandkeep.net/projects/diy-japanese-paper-envelope-styling • Posted by Estelle C.
Take the following measures from your envelope to determine the shape of you Japanese paper: Width - 2 times 2mm (2mm less on each side) Height from the folding line -2mm Triangle dimensions with a 1cm offset as shown on the last picture below, to keep the sticky part free. Prepare your shape following these dimensions and cutting the two lower corners.
Insert the Japanese paper inside the envelope and glue the triangle part only. No need to glue the bottom part, it will stay in place inside the envelope. And that's all there is to it! Pretty easy right?