Several years ago I saw someone with a scarf that was made just of yarn sewn together. They told me their friend had made it using dissolvable interfacing. I had that in the back of my mind for a long time and recently saw the technique again in a recent issue of Spin-off magazine. I decided to finally try it out on my yarn that I made while trying out my drum carder. You can read all about making the yarn here.
After the yarn was done, I arranged it and sandwiched it between two pieces of dissolvable interfacing and pinned it to keep it all in place. Then I sewed back and forth on my sewing machine.
Finally, I just ran cold water over it to dissolve away the interfacing and hung it to dry!