The e-wrap cast on or backwards loop cast on is a great cast on to use when casting on within a row. It is very unstable, which makes it disappear, but also makes the e-wrap cast on quite difficult to knit into! This is often the first cast on a knitter learns because it is so easy to cast on, but the difficulty of knitting into it on the first row overcomes that ease. When you have the e-wrap or backwards loop cast on to knit into, loosen the yarn by twisting the loop around your left needle in the opposite direction to make it easier to put your right needle into the loop.
E-wrap or Backwards Loop Cast On
These are the instructions for casting on to begin your knitting: With yarn tail and needle in your right hand, pick up the yarn in your left hand, keeping your left thumb free. *Bring your left thumb behind then underneath the yarn and bring the right needle towards you to create a closed loop on your left thumb. Now, put the right needle into the loop on your thumb from underneath, taking your thumb out of the loop and gently tightening the loop onto the needle. Repeat from * for the correct number of stitches.
Slightly modified for working the e-wrap or backwards loop cast on within a row: Pick up the yarn in your left hand keeping your left thumb free. *Bring your left thumb behind then underneath the yarn and bring the right needle towards you to create a closed loop on your left thumb. Now, put the right needle into the loop on your thumb from underneath, taking your thumb out of the loop and gently tightening the loop onto the needle and to the existing stitches. Repeat from * for the correct number of stitches.
As the e-wrap cast on goes onto your right needle it looks like a lower-cast e.
See also: long tail cast on, e-wrap or backwards loop cast on, flexible long-tail cast on, cable cast on