Elastic Chair Webbing, 2 in Wide, Black, 32, 40 or 160 ft Roll

Elastic webbing is the springy support under the seat cushion on many mid-century chairs, Danish lounge chairs, dining chairs and sofas. When the old straps go slack or brittle, the cushion sinks into the frame. This black rubber-latex webbing is 2 in wide and replaces them strap for strap.

Before you take the old straps off, photograph the frame from underneath. Count the straps, note which way they run, and see how they are fixed: metal clips set into a slot in the frame, or tacks into the rail. The new straps go back the same way.

Fitting it:

• Measure the span each strap covers, from fixing point to fixing point.
• Stretch each strap about 5 to 10 percent. In practice that means cutting it 5 to 10 percent shorter than the span, then adding what the clip or tack needs at each end.
• Fix one end, pull the strap to length and fix the other. Keep every strap that runs the same way at the same tension.
• If the old straps were woven in both directions, weave the new ones over and under in the same pattern.

Too little stretch and the seat sags as soon as someone sits down. Much more than that puts extra strain on the frame and the fixings.

Reuse the old clips if they are clean and not bent, or fit new ones. Cut the webbing square across with sharp scissors so each strap sits flat in its clip.

The roll comes in 32, 40 and 160 ft; the long roll suits sofas, sets of chairs and workshop use.

Work out how much you need from the frame. Count the straps, measure the span of each one, take off 5 to 10 percent for stretch and add what each end needs for its clip or tack. Add the straps together and allow a strap or two extra for mistakes.

For example, six straps across an 18 in frame, each cut to about 17 in, use about 8.5 ft before the fixings. A seat and a back, or straps in both directions, take more.

Once you have a total, pick the roll that covers it with some to spare. The 160 ft roll is for sofas, sets of chairs and workshops.