How to: work two-colour cast on for double knitting

Double knitting is an interesting technique that allows you to create a fabric made up of two separate layers, yet knitted at the same time with all sorts of exciting opportunities for working with colour and texture. Stitches for both colours need to be cast onto the same needle at the same time.

There are several different ways to cast on with two colours, and this is a simple method that is similar to a long-tail cast on. In double knitting, colours are allocated to each side of the fabric. and we will call the Yarns A and B, one for each side. You will initially need one strand of Yarn A and two strands of Yarn B, so use both ends of Yarn B from the ball to start with.
Take the three strands and make a slip knot leaving a short tail. Put the slip knot on the knitting needle held in your right hand, and note that the slip knot does not count as a stitch.

Hold the left hand in the sling shot ‘C’ position of the long-tail cast on, by tensioning one strand of Yarn B over your thumb, and the other two strands (A and B) over your index finger. All the strands will be held by you lower fingers and note that the yarn held over the thumb – Yarn B in this case – will appear along the cast-on edge on both sides. After casting on, you will cut the thumb strand of Yarn B, and only continue working with the other strand, so if you have a preference of working from the inner or the outer end of the ball, make sure that this strand is held with yarn A over the index finger.
TIP To ensure the strands lay correctly over your thumb and index finger, try holding the strands with your lower fingers and then insert your thumb and finger between them.

To work this two-colour cast on, first insert the knitting needle up under the strand on your thumb, then use the needle to wrap the two strands around it from back to front. Pull the stands towards you and up through the thumb loop. Move the loop from your thumb over the tip of the needle and pull it tight by stretching out thumb. This has cast on two stitches, one of each colour, in one go.
Repeat this action, making sure that Yarn A is nearest the needle tip end in each pair. It may help to smooth out the yarns strands every few stitches to keep the order of yarns correct, or use a tapestry needle to lift one over the other, without stretching the loop, to make the sequence correct.
After casting on the correct number of stitches, cut the solitary strand of Yarn B held that was held over the thumb. You are now ready to start working your pattern.