The stockinette stitch (or stocking stitch in the UK) is one of the basic stitches when you learn to knit. It’s so basic that most patterns won’t explain it. You might see Stockinette Stitch abbreviated in a pattern as St st.
The stockinette stitch is formed by one row of knit stitches, one row of purl stitches. It has a right and a wrong side, depending on the intend design. The right side is typically the side with ‘v’s and the wrong side is the side with waves.
Row 1, knit
Row 2, purl
repeat row 1&2 for the pattern
The stockinette works on any number of stitches. The knitted pieces would curl. The top and bottom (horizontal) edges curl toward the right side, the ‘v’s side. The side (vertical) edges roll toward the wrong side, the wave side. You can either use the curl as edging, or add a border of ribbing, garter stitch or non-curling pattern to the edges.
My patterns using the stockinette stitch:
4-color Block Baby Blanket
All About Stripes Baby Blanket
Gradient Stripe with Bird Long Sleeve Kids Sweater
Oat – Mommy and Me Family Matching Sweater