astronomerroyal

Unsolicited thoughts:

I also tried using elastic webbing, but in the end I found simple bungee cords to be more useful/versatile. I use a duffel bag for something like touring and a rubbermaid tub for groceries, neither of which warranted an elastic net, sadly - although it is attractive idea. For the most part I use built-in nylon straps with adjustable buckles for strapping purposes. Most useful by far. I think I posted a p[iiicture with these straps somewhere on this thread.

As for the bed material, I found that Makrolon polycarbonate works well (for my sidewalls). I would think 1/4" would be a good thickness for a bed, perhaps more if it's entirely self supporting.
that would be almost indestructible, although I expect some sort of wire mesh would actually be lighter (I use wire mesh for my trailer bed, but it might sag if it doesn't have some support i.e. crossbeams).

Those trailers look really well designed.

Sincerely,
AR.