The single shuttle plaid idea comes from using a sliver with several colors side by side and spinning a different color with each arm’s length draw. I was both a new spinner and a new weaver at the time, and weaving with my handspun helped me improve my spinning. My early spinning was not spun tightly enough to hold together with a tug on the shuttle. Not only that, my spinning was very inconsistent, which was very evident in the wavy selvages. Here's a photo I call “waisted energy”.