| A quality chair or sofa will employ some type of inner | | | | parallel to each other and are fastened directly to the |
| spring system, usually in the back as well as the seat | | | | frame and to each other. Similar to this system is the |
| area. These systems add comfort, as you might | | | | formed wire spring, whereby the continuous wire is |
| expect, but they also work to take some of the stress | | | | formed into rectangular bends and angles instead of |
| off the joints of the frame. Here are some of the | | | | the zigzag pattern. |
| spring systems being used: | | | | Finally, the grid suspension system is composed of a |
| First up, we have the coil or cone spring system. This | | | | wire grid, sometimes covered with paper or |
| quality system uses eight-way, hand-tied double cone | | | | plastic-coated wire, which has one side fastened |
| springs to provide extraordinary comfort and support. | | | | directly to the frame. The other side is connected to |
| This technique involves fastening the cone springs | | | | the frame by helical springs. This is also a very |
| tightly to the base and expertly tying their tops | | | | common system that is used widely. |
| together with a strong cord. This is the only system | | | | If a chair or sofa doesn't use one of the |
| that allows for side-to-side movement in addition to up | | | | aforementioned inner spring systems, it's probably a |
| and down movement. Hand-crafted quality comes at a | | | | good idea to steer clear of it. Some manufacturers |
| price, though, and while this is widely considered the | | | | use elastic webbing instead of wire springs. The strips |
| best spring system, it is also the most expensive. | | | | of elastic usually intersect and weave together and |
| Next, we have the sinuous wire spring, which is made | | | | are fastened directly to the frame. It is best to avoid |
| in a continuous zigzag or "S" shape. These wires run | | | | furniture that uses this technique. |