Fair Isle
From WikiKnitting.com
[edit] Introduction
Fair Isle knitting is a technique where two colors are used in the same row to create a pattern or motif in the fabric. It is also called stranded or jacquard knitting.
[edit] How it's Done
The knitter carries two live colors in their hands. While knitting with one color the knitter carries the other color behind the work until it is needed again. Once needed, the colors are swapped and now the original color is carried behind the work.
This creates a series of floats on the back of the piece that is characteristic of this technique. These floats are usually less than 5 stitches in length. This is usually small enough that the floats can lay relatively flat against the material and not get caught on anything. This distance also helps keep the tension of the finished fabric even.
It is important to keep the strands in the back of the work loose enough that they do not pucker the stitches on the right side. One way to ensure strands that are loose enough is to occasionally stretch out the stitches just worked on the right needle.
This techniques lends itself well to circular knitting and is not commonly used in flat knitting.
While more than two colors can be used in a single row, it is cumbersome and is not common. If you want a pattern with more than two colors, the color changes are done using a different pair of colors on each row. Any unused colors are can be carried up behind the work at the beginning of the row so that they can be used again in later rows.

