The three needle bind-off is a knitting technique for binding off, or finishing, two pieces together so that a seam is created between them. This technique can be used with any type of wool or knitting project, as long as the two pieces being bound off together are of the same gauge. The three needle bind-off is commonly used on the shoulders of sweaters, hats, and other knitted pieces that often endure more stress than other seams.
While somewhat complex to learn, and even more difficult to explain, the three needle bind-off is an excellent knitting tool, making for neat finished seams and a stronger overall garment. While the three needle bind-off is more labor intensive than other methods, the effort results in a garment of higher quality and is well worth it. The three needle bind-off intimidates some knitters, but once learned, it's both fun and easy.
Any knitting project eventually needs to be finished in such a way that it won't unravel with use. There are a number of conventional bind offs designed for a single knitted panel that result in a smoothly knitted edge that will not ravel or appear uneven. With a garment such as a sweater, some knitters prefer to knit all the pieces individually, binding off the edges as they go, and then sewing them together at the end of the project. This method is perfectly acceptable, although it may result in premature holes in the garment. The three needle bind-off is strongly preferred for garments that are intended to be frequently worn.
With a conventional bind off method, the knitter knits two stitches and then slips one over the other, leaving one stitch on the needle. Then another stitch is knitted, and the previous stitch is slipped over that one, and so on until the end of the piece, when the tail of the yarn is pulled through the final stitch. The result is a neat line of bound off stitches that cannot be pulled out of shape, and the method is highly effective for scarves and simple garments for which no joining is required.
To perform a three needle bind-off, the knitter takes the two pieces to be joined while still on the needle, and puts them together with the right sides facing, so that the knitter is working the wrong side of the garment. The two pieces can be on two straight needles or together on one circular needle, depending on which is easier to handle. A third needle of the same size is required for a three needle bind-off, although it can be either single pointed or double ended.
With the third needle, the knitter picks up one stitch from each needle and knits them as though knitting two together, a common knitting stitch, and then repeats the process, leaving two stitches on the third needle. The first stitch is pulled over the second, the knitter picks up two more stitches, and the process is repeated until the end of the join. When turned right side out, the result is a smooth, even seam that will be difficult to damage or unravel and will lie smoothly on the wearer with minimal lumps or scratching.