It is important to remember that a piece knit in only stockinette stitch is inclined to roll at the edges (i.e. bottom hem and sleeve cuffs). One way to combat this is to insert a pattern in these places that is composed of knit and purl stitches on both sides. Barbara Walker’s first and Second Treasury of Knitting Patterns offer chapters on Knit and Purl combinations which can be used for non-rolling edges. The patterns in which the number of knit stitches and purl stitches are equal will defeat edge curling the most efficiently. Some good examples of these include:
A Treasury of Knitting Patterns:
• Pg 11: Seed Stitch, Moss Stitch and Double Seed St
• Pg 12: Broken Rib
• Pg 17: Basket Rib
• Pg 20: Swedish Check
• Pg 29: Lozenge Pattern
A Second Treasury of Knitting Patterns:
• Pg 6: Belt Welt
• Pg 8: Little Pyramid
• Pg 13: Moss and Rib Block Stitch (version II)
While there are a multitude of other patterns that will not roll in these books, the ones listed above are some of the least complicated and will keep the gauge consistent. Rib patterns also will not roll, however, they will pull the fabric in where they are used, so this must be taken into account.
Another important factor in keeping the edges flat, is the type of cast on that you use. Using the long tail cast on and keeping the stitches on the tight side while casting on will also help to eliminate rolling.