I’d say it looks like a layer of burlap, then cotton on top of that 3 or so layers, muslin if you want to hold the cotton down, then appears to be foam on top of that.

If the customer is not a purest, another option would be burlap, jute , one inch foam, with a dacron top layer. We use this method with great results.

Thanks!
This sounds like the best option, thanks!

check out this one I had to do https://www.rodsnsods.co.uk/forum/topic/whats-trim-shop-week-32177/page128

Hey Chris, I was just scrolling through the pics you had in that link you provided. That is a great idea using the heim joints for the center backrest hinge pins. I'm going to put that one to use in the future.

your welcome ………..………… it was the only way I could see that it was possible

I use the same method as Gordon but I use a foam bun. They have a skin on one side and stiffens the seat and evens out the weight. Plus they are cheap.

@Peter Pittel do you have a link to the foam buns? I think I know what you’re explaining.

@Cody Lunning I get mine from either Rochford Supply or FSI in Minneapolis. What they are is the top and bottoms of the foam when it is made. They have a firm coating. https://www.fabricsupply.com/products/foamskins-high-density/