I found my justification - I was already looking toward a canvas dining fly as my next camp upgrade. A large tarp that could serve as a fly could also be set up as a tarp tent.
Now I'm focusing down on what weight canvas do I need, and how am I going to treat it for water and fire resistance. Some people apparently use painter's tarps for tentage - that's only 6-10oz canvas. Painter's tarps are actually fairly inexpensive for a 9x12 ($15-$25) - I could just get one and try it out, and if it's not good enough, it's not a great loss.
Net (Macrame) Bag
Last year, I wanted a mesh bag for Pennsic - seems like it could be useful for holding produce, or wet soap, or something. This year, I made one. I strung a piece of hemp cord about 2' long and tied thin cotton cord in two half-hitches at ~1" intervals, so that there were two 'tails' of cord per knot. Then, used a series of square knots to make the mesh. I made it into a bag by fastening the sides together, then gathering the 'bottom' - the hemp cord got tied into a circle to make the opening of the bag.
It's kind of ugly (I tried to use a wooden gauge for consistent mesh, but couldn't figure out how to hold it and tie knots) but it works! I think using the square knots makes this macrame rather than true netting, which (from a very brief look) seems like you're supposed to be able to make it using just one thread carried on a netting 'needle.' (It winds up like on a weaving shuttle.) Anyhow - I have my bag.
I made a spindle out of a bamboo skewer, a piece of paper, glue, and a glass bead. The paper was glued on and wrapped around the skewer to pump up the diameter, so the bead would stay in place. I used it for supported spinning, using a small bowl. There was no hook on the end, so I'd just spin in the same direction as the thread was winding around the spindle. That created a tendency for the yarn to try and wind itself up towards the top of the spindle, which I tried to counter when I wound the thread on intentionally after drafting.
I wonder if I got the medieval technique? Immediately after spinning, I did have to use the 'draft and pinch' method Baroness Emma showed me. But after the really aggressive initial twist petered out, I could just slowly puuuuull the spindle away from the roving, and fibers flowed out and twisted up. The yarn tended to thin out as I went, so sometimes I had to manually encourage more fibers into the flow. But it felt like those pictures of the ladies with their arms apart and a slightly bowed thread between them.
I'm signed up for a drop spinning class at Colonial Williamsburg next week, just for fun. :)