Many latex purest may think there is no point in putting a quilted layer on the surface of a latex core. The argument is that it is the ultimate comfort layer and should be as close to the surface of the mattress with little or no urethane foam, polyester fiber, wool or cotton fiber between the sleeper and the latex below. Before I address the benefits or lack thereof of any of those materials it is important that we address compliance to CFR 1633 open flame tests.
As you probably know all mattresses made and sold in the United States have to be in compliance of the 1633 regulation. Latex is an interesting animal, it requires not only surface flame resistance, but thermal heat resistance. Urethane foams only require surface flame resistance, but do not require thermal resistance. This enables urethane foams to achieve compliance with very thin knitted socks, however latex needs something thicker which will block thermal transference of heat. Insulation similar to but not as thick as you place in the walls or attic of your house. There have been advances in thermal protection that are thinner than was originally required, however it is still thicker than the thin socks that will protect urethane foam. My point is that in latex mattresses sold in the USA there will always be something more than just the outer covering.
OK, now we can address the benefits of other quilting materials that are optional and not required by law.
Urethane Foam: In my opinion in most if not all case definitely no. The manufacturer is only adding additional fluff to make the mattress more cosmetically appealing. However, you lose many of the benefits of sleeping on the latex, which is what you are paying for.
Polyester Fiber: Again, in my opinion my response is the same as with urethane foam, No real benefit only cosmetic appearance enhancements.
Wool Fiber: In this case there are real benefits. Wool is warmer in the winter and cooler in the summer. Wool naturally wicks moisture away from the surface of your skin, making you sleep cooler. 100% wool in the proper thickness will actually pass the 1633 FR tests. Wool is flame resistant and in the proper weight will offer sufficient thermal insulation to meet the open flame test requirements.
Cotton Fiber: In this application using cotton quilted into a cover that sits between the sleeper and the surface of the latex core, I simply don’t like it. Cotton unlike wool is a much firmer fiber than wool batting, so in effect you very much compromise the soft latex comfort layer.
In conclusion, wool or a thin FR sock is the best way to go on a latex mattress. Wool and latex are really the perfect marriage for achieving surface feel with a great natural story.