There are 4 layers in a ‘naturally’ upholstered cushion:

  1. The innermost latex foam cushion core,
  2. The wool batting that wraps the foam,
  3. The ticking fabric between the wool and cover fabric,
  4. The outmost upholstery fabric.

Latex.

We’re talking natural rubber. Sap from the Hevea Brasiliensis tree, native to Brazil, but now grown across southeast Asia.

Tapping latex from a rubber tree (Hevea brasilensis) is similar to tapping sap from a maple tree

If you’ve got an old chair from the 30’s, 40’s or even 50’s that has never been re-upholstered, chances are the cushions are stuffed with either traditional upholstery materials (horsehair, cotton or spanish moss) or latex foam. Urethane and Styrene Butadiene Rubber (SBR) foam were developed in the late 30s – early 40s, but it wasn’t until 1959 that natural rubber production was overtaken by these synthetics (info from bouncing-balls.com) – but we’ll save the synthetics & blends for another conversation. For now we’re just focusing on 100% natural latex.

Natural latex is biodegradable.

In fact it breaks down quite rapidly in sunlight. I’ve even seen fluorescent lighting turn an unprotected block of latex into a crusty, powder-shedding mess in less than 5 years. The bottom line: Latex foam does best in the dark. If your cushion is wrapped properly to protect against UV’s (just the cover fabric is not enough) it should last 20 years or more, so you can look at it as a long-term investment. Just be sure your chair or sofa is built to last that long.

By the way, high heat will degrade latex too, so best not put in the dryer or right next to a room heater.

Four benefits of wool batting.

I recommend using natural wool batting with your 100% natural latex foam. I like to think of it as gift wrapping with a three-fold purpose. By wrapping your cushion with a generous (1-1.5”) layer of wool batting, you are:

  1. Protecting your latex foam from UV exposure
  2. Providing a NATURAL flame barrier that meets the revised CA TB117-2013 standard for flame retardants in upholstery
  3. Softening the edges of your cushion (as conventional polyester batting does in standard upholstery practice)
  4. provides enough coverage to prevent the latex holes from showing through the cover fabric.

Why ticking?

Wool has barbs which are oriented in one direction on each fiber. When a single fiber sticks through the surface of a fabric, if orientation is right, the barbs will cause it to continually work its way out, where it will tangle with other fibers causing an unsightly ‘pilling’ on the surface. If you’ve ever seen this phenomenon, you’ll know what I mean – it’s a frustrating situation.

a single Wool Fiber as seen under a microscope-medicalsheepskins

The barbs on a wool fiber as seen under a microscope (medicalsheepskins.com)

Fortunately pilling can be prevented by using a tight-weave ticking fabric that will not allow wool fibers through – much like a down-proof ticking. You can use this in the construction of your cushion in either of two ways:

  1. If you’re re-using an existing cushion cover, sew a separate inner cushion cover from the ticking (make the cover just slightly larger than the outer cover so it fills to the edges)
  2. If you’re building a new cushion cover, cut the ticking fabric at the same time as the outer upholstery fabric, and sew the two layers as one piece. you can even serge the two together at the edges for easier handling.

This is only part of the entire latex story, which I will unfold for you in future posts. If you’re thinking of replacing your old cushion foam with latex foam, you can find free downloads and video instructions for measuring linked from this page.

If you have any questions that aren’t answered here, you might like to subscribe to the mailing list to receive tips, class notifications and videos about natural materials for upholstery.