Three Envelope Mockup
The best Envelope Mockup allows you to showcase your front and back envelope designs in a single mockup. Simply use smart object option for the design insertion and use well-named layers for the rest of customizations.
Free

The best Envelope Mockup includes three envelopes for the front, the back, and the open view. You can also change the color of the envelopes themselves, their inside, the pencil, and the background.