That looks interesting, Dave. What type of material is that? It looks like heavy fabric...cordura?
No, it's a piece of left over pond liner.
Needing some material that was opaque, stiff enough to stand when folded yet flexible enough to collapse if I get clumsy, I looked for neoprene or butyl rubber sheeting, which only seems to be available in industrial quantities. Then I found I had this in our store at the bottom of the garden and it is ideal. I think it is MDPE.
Now I can use the EVF with both eyes open!
Dave