Wide Rib (multiple of 10 sts plus 5)
Note: the instructions below are a generic description of how to execute this stitch pattern. For a single repeat, you'd only need fifteen stitches but you'd have a VERY narrow piece! In the example shown, there are three repeats of the stitch, so to make a swatch that looks like the one shown, you need to cast on 35 stitches (3 x the multiple of 10 stitches needed for a single repeat of the pattern plus five extra stitches.)
Row 1 (RS) P5, *k5, p5; rep from * to end.
Row 2 K the knit sts and p the purl sts.
Rep rows 1 and 2.
Stitch directions reproduced with permission, from Vogue Knitting Stitchionary: Volume One, Sixth & Spring Books, 2005