This is a straightforward design:
- Knit a swatch to check your guage.
- Cast on enough stitches to be 1/2” smaller than the length of the portable device you wish to cover
- Garter stitch a rectangular shape that can wrap around the device.
- Complete the “top” of your rectangle with k2 p2 rib for about two inches.
- Bind off these rib stitches. Sew the side edges so they overlap, right sides facing, just like a slipcover for a pillow sham. Turn right side out and block as desired.