Ron, just got the 4'4" X 9'6" spin tarp (rectangular, no seams) from you, very nice thanks! Your craftsmanship is superb, I am very impressed.
I'm glad you posted this because I was thinking of cutting it in half for a 4'4" X 4'8" tarp for use in conjunction with a waterproof bivy.
I use a bivy but also like the extra headroom/protection a tarp gives so I am not trapped in the bivy during rain or melting in hot sun when hanging out at camp.
So really (with a waterproof bivy), I just need upper torso coverage (some for my dog to sneak under too). At 4'8" long I could get about 1'5" past my head for vestibule and the rest over my torso, with the usual spin width at the sides.
Obviously, without a waterproof bivy this concept won't work too good in rain, but those are getting lighter with eVent. Maybe even just the lower half waterproof even.
Yes, one could use a hooped bivy with a mini dome, but the tarp option gives more versatility IMHO.
What do you think of this idea?