The Tempur-Pedic original mattress was eight inches thick and had two layers. The top layer is composed of three inches of 5.3-lb. visco-elastic foam that had a listed ILD rating of 14. The bottom layer of the mattress was composed of 5 inches of 3.5-lb., non-visco elastic, high density polyurethane foam. It included a cover that is composed of a soft, cotton-like material that was stretchable. To prevent voiding the warranty, Tempur-pedic mandated that their foundation be purchased with their mattress.
Tempur-Pedic now offers Tempur-HD, a 7.0-lb. density memory foam that is more temperature sensitive. It will feel firmer until it adapts to your body temperature, especially in cooler room environments. At the end of 2009, they came out with the Cloud Supreme mattress, which utilizes the same multi-density, memory foam layer design of the Tri-Pedic, a mattress that came out from Selectabed.com in 2002. Both mattresses utilize 2 inches of 4-lb. density memory foam that is bonded to 2 inches of a 5-lb. density memory foam. The reason for the 4-lb. density is to offer a less temperature sensitive and more plush initial feel.
Other companies are now offering a two layer 1-lb. to 8-lb. visco-elastic material, and some even offer other types of materials that are layered throughout the mattress. They also offer a wide variety of ILD ratings, but the most common are 8-20.
They are using everything from the thinner cotton and/or bamboo rayon cover, to a bulkier wool or quilted cover. While these bulkier covers will feel softer to the touch, the disadvantages are that they will take away from the memory foam feel and contouring of the body. Wool covers will be warmer in the winter and hotter in the summer. The cotton type of covers can wick away moisture, but you may want to get an easily removable one, so you can wash it every so often. They offer thinner and thicker sizes, but eight to 10 inches usually suffices. If you have a solid platform base already, then it is not necessary to order one at the time you make your purchase. However, you may need to order one if you lose integrity in your base down the line.
With all of this said, perhaps the biggest reason many consumers choose to go with a different mattress company would be price. While Tempur-Pedic® is not the most expensive one out there, there are companies offering memory foam mattresses at significant price reductions. When the price is less, it falls on the consumers to do their homework and evaluate the price in relation to the memory foam quality, using measures like density, real 3rd party testing performed on the memory foam, and noting where all the components of the mattress are made, so as to properly discern the true value of the product.
You can browse through a list of mattress companies who offer Memory Foam Mattresses, mattress pads, and other similar products by clicking here.