The purl front-and-back is an easy increase which is nearly invisible when used on Reverse Stockinette stitch.
- With yarn in front, purl the first stitch on your left-hand needle but don’t remove it from the needle.
- Stabilize the stitch with your finger.
- Insert your right-hand needle into the back loop of the same stitch.
- Purl the stitch and remove both loops from the left-hand needle.