Fold Letter Into Envelope. Fold the letter in half lengthways with the message inside the folded paper so it. Rotate and fold corners i’ve drawn a line on the middle crease just to help you see it better.
Once you have a rectangle with your various folds on one side its time to create the functional part of the envelope. A letter that is more than 4¼ inches high or 6 inches long and is less than 0.009 inch thick. Repeat on the left side.