Elastic webbing as sofa suspension?
I bought a sofa made by Italsofa (Natuzzi's budget line).
The closer to the center that you sit, the further you sink into the couch. I looked in the manual and saw that the suspension was made with elastic webbing. I assume that the sinking is caused due to the elastic straps being tied to edges of the frame with no other support in the middle.
I know I bought a "budget" couch but expected it to make it until I had paid my credit card bill before it started sagging.
Is this a legitimate way to make a couch? Is it defective? Or is this normal/acceptable? Does it have a reasonable longevity?