Polyester tablecloth fabrics will not stretch.

These are available in 156"x90" and all you have to do is to get a seamstress to sew a channel (I use four stitch lines to ensure integrity).

That is a 13-foot long hammock (minus the two channels), so make it 12-foot 8-inch in length.

https://tableclothsfactory.com/produ...12639782699093

I can add a link to some images in another thread on this site if you have an interest.
IMG_1415.JPG

I use two of these so that I do not need underquilts, those sleeping bags are synthetic 0-deg F and quite heavy. Very warm though.