There are many types of sewing stitches used in knitting. Most sewing stitches are used to sew seams together when finishing pieces, or as a decorative element. The backstitch is one of the strongest and sturdiest sewn stitches, and for that reason, it is not always the best option for seaming knits due to it’s inflexibility. There are lots of uses for it though!
Use the backstitch to sew together two pieces of knit fabric together or as a decorative element on the right side. Unlike the mattress stitch it is not an invisible seam, but the backstitch does create an extremely strong seam.
How to sew a backstitch
Set Up: Orient your fabric so the edge or area you will be sewing along is horizontal, and to the top. Thread your tapestry needle and bring your tapestry needle to RS of fabric leaving enough of a tail to weave in later. Insert needle to the left or right of where the needle comes out on the RS approximately 0.125 inches away, and draw through the fabric to the WS.
Repeat: *On the WS, insert the needle to the right or left of where the backstitch ended on the RS approximately 0.25 inches away. Draw the needle through fabric to the RS. Insert the needle to the left or right as in the setup. After each stitch be sure that the thread or yarn is not pulling. Repeat from * to the end of your seam.
Finish: Work in both ends.
The backstitch will show on the WS as a long running stitch. The length of the stitches can be varied for many different applications. The backstitch is related to the pick stitch or stab stitch, which are more decorative versions.
Running stitches can be hidden when two pieces being joined. Take the needle to the WS through both layers, then take a small stitch on the WS, bringing the needle between the two pieces. The needle is brought through to the RS of the top piece in the desired location.