Back of the Envelope using Graph Paper Sep 2026

I made my own envelope suitable for back of the envelope engineering calculations.

Only folded paper; no special cutting; made from rectangular 8.5 x 11 paper. The ruler wasn’t used in folding, its only shown for size reference.

In my example, the final dimensions are 5.75″ x 3.5″, therefore a legal USPS envelope.

Special thanks to Easy Origami Envelope From 8.5″ x 11″ Paper.