Last spring I attended PlyAway. I learned a lot but wasn't sure much of it stuck in this sieve-like brain of mine. One idea I did retain was plying with silk to create a stronger yarn for weaving. I finally actually tried this out - well, the plying part, not the weaving part, yet.
This is a 3-ply yarn. Two plies I spun from some unknown roving, the third is commercial silk. I'm pleased with the results. (For the record, I spun this on my Ashford Joy 2 wheel, one notch down, then plied it on the same wheel but an additional notch down.) The silk adds a bit of sheen to the yarn, which I hope you can see in the photo below. If I were spinning a thicker yarn, the silk would probably disappear into the wool.
The logistics of adding the silk ply were surprisingly difficult because the silk was on a cone. I tried to simply put the cone on my 3-bobbin lazy kate, but the brake wouldn't keep the silk from spooling off too fast. I eventually unspooled some silk onto a swift but I had to put a rubber band around the shaft to keep it from spooling off too fast. If I decided to do more of this, I will just put the silk onto a bobbin of its own so I can put it on the lazy kate with the others.