Test its sturdiness. Quality sofas should feel solid and heavy. Flop around on one to test its sturdiness, then lift it up by the corner and shake it a bit.

If it feels light or wobbly, take a pass. Look for a frame made from a kiln-dried hardwood such as oak, alder, birch, maple or, alternatively, high-quality hardwood plywood or marine plywood. Eight-way, hand-tied springs are a hallmark of fine furniture, but sinuous S-shaped springs can provide nearly as much comfort. Drop-in coil springs are a less costly alternative.

Most sofas have sinuous, also called serpentine, springs preassembled units of snaking wire. They're nicely supportive, but they can press on the frame or sag over time if the metal isn't heavy.

High-end sofas often come with "eight-way hand-tied springs." They're comfy but expensive; some experts feel they're no better than serpentines. Feel the springs through the upholstery they should be close together and firm. Sofas with no springs, just webbing or mesh, are uncomfortable and flimsy.

What makes a flexsteel sofa. SEAT SPRING. Our exclusive, lifetime-guaranteed blue steel seat spring delivers unmatched comfort and durability. And, unlike eight-way hand-tied springs, it never needs retying or replacing to keep you from getting that sinking feeling a few years from now. ARMS.

Sofa in and out arms lined and padded for ultra comfort. HIGH RESILIENT PLUSH CUSHION. The Plush Cushion features 2.5 lb. high resiliency polyurethane foam topped with 1.2 lb. density polyurethane foam and a 1 oz. fiber wrap – all in a white fabric wrap.