You can fashion a large envelope from any sturdy paper in a variety of designs. The simplest to make entails wrapping a large sheet of paper around the item to be mailed and neatly gluing or taping the edges. You can also employ a template to make an envelope; any carefully opened envelope can become a template for a new one. Personal expression can become part of envelope construction when you choose your own paper patterns and colors. Just remember that the post office needs your creation to be tidy so that it will flow effortlessly through the mail.
Open any envelope to use as a template. Loosen and lift all glued flaps and flatten out the whole envelope.
Place this template on the paper you choose.
Trace around the edges of the unfolded envelope.
Draw the inside lines with a pencil and ruler. These will become the fold lines. Use the original envelope as a guide by refolding each part and noting the positions of the folds. With the original envelope on top of the new paper, make small marks to indicate both ends of each folded line.
Cut the paper along the outside lines with scissors.
Score the inside lines with a letter opener or any object that will make a slight indentation but will not cut the paper.
Fold the side flaps in.
Bring the bottom flap up and fold it firmly.
Apply white glue to the overlapping paper sections.
Place a heavy book or similar object on top of the envelope to press the envelope flat as the glue dries.
You may want to neatly apply tape to the seams for further reinforcement.