The true knit stitch (aka reverse purl) is often used in loom knitting patterns. It creates a stitch that is smaller than the stockinette stitch but slightly bigger than the uknit or flat knit and the same size as a purl stitch. It works really well for a ribbed pattern of Knit 1 Purl 1 or Knit 2 Purl 2. Here is a quick video to show you how to do this important stitch.
