The three-needle bind off method is used to cast off and finish two knitted pieces that you’d like to join.
This means it is both a bind off and a seam.
In addition to being a practically invisible seam, the advantages of using this type of bind off are that it gives a certain strength to the “seam” and that it makes it much more difficult for a garment to come undone and end up with holes.
So that the seam is on the wrong side of your work, place the two pieces that you want to join with the right sides facing, as shown in the photo.
-The right sides are facing each other and the wrong sides are facing you.
Situate the needle parallel to each other above the work and insert the third needle into the first stitch on each one of the two needles.
Place the yarn as if you were going to knit and knit the two stitches together. Drop the stitch from the left needle as if you were knitting a completely normal stitch.
Repeat this step to get two stitches onto your “extra” or third needle.
Now with one of the needles in your left hand, pass the first stitch over the second, as you normally would when you’re casting off.
Repeat these steps until there are no stitches remaining.
It’s important to keep in mind that you should have the same number of stitches on each one of the pieces that you are going to join so that you don’t end up with wrinkles. It’s also convenient if your third needle is a larger size than the other two, because working with three stands at a time can cause the stitches to become too tight.
As you can see, all we’re doing is casting off stiches in the same way that we usually do while also knitting together two stitches from each piece.
Now you know another way to join pieces on your next garment!