So you've got to the stage of a bottom-up cardigan or jumper where you're going to cast off the shoulders. Later on, of course, you'll need to join the shoulders together. Two jobs to do. Wouldn't it be useful to be able to do both of them at the same time? It's useful, and it's also a very good idea, because joining the two pieces as you cast off gives a firm, pleasing and very stable connection - ideal to bear the weight that the whole garment will place on the seam. The technique in question is called a three needle cast off, and here's how you do it. You need the live stitches for both parts of the "seam", so put the last row of your front on a stitch holder while you complete the back or vice versa. The two final rows must have the same number of stitches. And you'll also need a third needle, the same size as the ones you used to knit the pieces, or maybe a size larger if you tend to cast off tightly. Put the needles that hold your two pieces parallel, with the right sides of the knitting facing each other. Then insert your third needle into the first stitch on each needle, so you're poking it through two stitches at the same time. Wrap the yarn around your right hand needle, and knit the two stitches together. Then repeat this knitting two together, so that you have two stitches on the needle in your right hand. The next step is exactly the same as a standard cast off - using the tip of the left hand needle (either of them!), leapfrog the rightmost stitch over its neighbour to its left. One stitch cast off! Then knit two more stitches together, one from each needle, just as at the start, and repeat the leapfrogging. That's all there is to it! When you've done a few, stop and admire your handiwork: a neat little seam which has accomplished your goal of casting off and making your seam in one easy step. Turn the work to the right side, and you'll see the seam we showed you at the top of this post. So, are you ready to give it a try? If you'd like to learn more fun and impressive finishing techniques then pop along to our shop in Dublin for our regular "Finishing School" workshop. You can view our class schedule online here.