An i-cord is a knitted tube that can be used as a tie, as a cord through a drawstring opening, as a border around an item such as a cushion or even as a fake cable decoration. They are easy, although a little time-consuming to make, and often create the perfect finishing touch for a knitted item.
I-cords are usually made with knit stitches and are worked on two double-pointed needles that should be two sizes smaller than the needles normally used for the yarn. To make a tie you will need to knit a short length, but for other purposes you can create as long a cord as you need. You can thread piping cord through the knitted tube to make it firmer if you want to use the cord to edge a cushion or make handles.
Use two double pointed needles that are two sizes smaller than the recommended needle size for the yarn. Cast four stitches onto one of the needles in the usual way. An i-cord is usually worked from four stitches, or you can use three stitches for a finer cord and five stitches for a thicker one. More than five stitches is not recommended.
Knit one row, do not turn the work but instead transfer the right-hand needle to the left hand and push the stitches down the left-hand needle from left to right so that they are nearer the opposite tip of the needle.
Bring the yarn across the back of the stitches and pull it tightly. Knit the next row. Repeat the process of sliding the worked stitches up the needle without turning it and taking the yarn back across the stitches to work the next row.
Working in this way will produce a tubular piece of knitting and you need to continue until you have created the desired length. Cast off the stitches in the usual way to secure the end of the cord neatly. You can thread the tubular fabric with piping cord if you want to make it more rigid for use as a decorative piped edge around a cushion.