Stockinette stitch will roll on all edges, that is why blocking is almost
Stockinette stitch will roll on all edges, that is why blocking is almost always necessary. The cast on edge and bind off edge will always roll towards the stockinette stitch side of the fabric. While the vertical selvedges of the fabric will roll towards the reverse stockinette side of the fabric.
This roll can be an asset as in the Rolled Brim Hat pattern in this section. That pattern uses the roll of the cast on edge as part of the design of the hat to create a brim.The rolled edges that form along the selvedges will pose several different kinds of problems. These rolls can make seaming more difficult as they must be unrolled as seaming progresses or the piece blocked before seaming to make those stitches and rows more visible.
If that selvedge is not going to be seamed, then several options are available that use a border of mixed stitch techniques such as ribbing, seed stitch, garter stitch, or moss stitch. The mixing of knit and purl stitches in the same or adjacent rows will usually force the fabric to not roll on that edge.
Button bands on cardigans are a great example of using these various stitch pattern as a control measure. Scarves frequently used these various stitch patterns as design techniques that add interest to the design but also have a job to do in keeping the edge flat
