The thread and needle are then again moved forward, so creating a series of overlapping stitches. Outline stitch is very similar to stem stitch, but the difference is that the working thread lies above the needle, while in stem stitch it is always below. The resulting line of stitching twists in a direction (S-direction) opposite to the stem stitch (Z-direction).
Source: THOMAS, Mary (1934). Mary Thomas's Dictionary of Embroidery Stitches, London: Hodder and Stoughton, p. 154.
Digital source illustration (retrieved 30 May 2016)
GVE