Normally, we are working stitches through the front loop or the part of the stitch that is on on the side of the needle closest to you. Sometimes a pattern will tell you to knit or purl through the back loop. In the video tutorial below, we show how to knit through the back loop, how to purl through the back loop, and how to switch between the two. We also take a look at the different fabric created with normal knits/purls versus knits/purls through the back loop.
Knitting and purling through the back loop will create more stitch definition, especially when doing ribbing. Stitches done through the back loop lose a bit of elasticity, however, as the base of the stitch is twisted which pulls in and tightens up the stitch.
Beginners should not be intimidated by knitting and purling through the back loop! After learning the difference between front loop and back loop, and with a little extra concentration, you can mix and match normal and twisted stitches to create incredible details!