A sturdy frame provides an anchor for good seating support, while filling augments it.
You should always test the quality of seating support by sitting on a sofa before you buy it. It shouldn't sag, but provide good support in the seat and in the back.
- The best seating support is the eight-way hand tied springs system. The craftsman connects each spring to the adjoining one with a strong twine. The twine passes front to back, side to side and then diagonally in both directions thus tying each spring securely.
- Another method is sinuous spring construction. Sinuous springs are “S” shaped and run from the front of the seat to the back. These springs are supported by additional wires that cross from side to side. This also makes for a strong seat, and it might be the preferred option in a sleeker style as it requires less space.
- The third option is web suspension in which bands of webbing cross the seat and back. These are then attached to the frame to make a platform for the cushions. Webbing can be made of either natural or man-made fibers, and if used alone doesn’t make for very strong support. However, in better quality sofas, it used with a tensioner that fastens the webbing securely to the frame. The web suspension is the least preferable of the seating support options.