Sounds like a parachute is right up your alley. Not exactly waterproof, but 3M does make a product that can make it that way.

Other than that if money is no object, probably gore tex is the next runner up.

Or maybe you can luck out and find a old hot air balloon that isnt airworthy anymore?

I would advise against a parachute. They are noisy in the wind, you need to cut vent holes into them and that creates more noise as they blow around.

For our Domes we use old hotel bed sheets.
They are free.
They look good and can easily be dyed.
They are light weight, and make little noise.
They provide nice shade.

They take a lot of work to make and attach to the Dome.
If it rains you need to be ready with tarpaulins or plastic that you can throw over the top.

Other things I’ve seen work are:

Old vinyl bill-board signs cut and glued to make a nice skin.

Plastic panels with a foil overlay to reflect the sun.

Overlapping layers of silver tarps.

I’m sure there are a lot of other good ideas. I’m interested to see what other people post.


LM