This week's stitch for the Build a Seam challenge is Chequered Chain Stitch, which I found in one of my old embroidery books. It is basically a regular chain stitch but with a couple differences. For this one you thread your needle with two threads of different colours at the same time, as seen below.
Now, the other difference is that when making the loops, you are going to pass one colour under the needle point and let the other colour lie on top. Below you can see where the needle is above the grey thread and under the orange thread. Pull through both threads and you end up with a grey loop.
Work the next loop with the other colour under the needle point. In my example now I'm showing the needle above the orange thread and under the grey thread. Pull both threads through and I end up with an orange loop. Keep alternating until you reach the end of your seam. You will be able to get a better look at the pictures if you click on them to make them larger.
Hope you like this one - it is a bit finicky but different. Have fun!