Innerspring
Innerspring mattresses are the most widely sold, constructed of a network of coils (springs) for support and covered by one or more types of polyester, latex, or visco-elastic foam and polyester batting for comfort. The cover, or ticking, is stitched to the top padding, and can be made of many materials, including polyester, cotton-polyester blends, wool, damask, microsuede, or even silk. When shopping, pay attention to the stitching- a large quilted pattern on the top will feel a little more "cushiony," while a smaller pattern will tend to feel a little firmer. When shopping for an innerspring mattress, you'll likely hear references to "coil counts" - the number of coils used in the mattress. The point to understand here is that the firmness of the mattress is dependant on the number, conguration and spacing of the coils, as well as the gauge (thickness) of the wire used in the coils. Heavier-gauge wire or a higher number of more closely-spaced coils typically provides a firmer feel, while lighter-gauge wire or fewer, more widely-spaced coils will feel "springier."
Memory Foam
Memory foam mattresses have become extremely popular in recent years. Popularized by industry-leader TempurPedic, and since emulated by a number of other manufacturers, the foam technology was initially developed by NASA scientists to relieve the tremendous g-forces experienced by astronauts during blast-off. Millions of satisfied customers swear by the way memory foam conforms to their bodies, providing support where needed, and eliminating the pressure points that previously caused stiffness, tossing and turning, and a lack of quality sleep. Memory foam has also proven popular for those with allergies, as some brands, like TempurPedic, are treated to be resistant to dust mites and other allergens. Memory foam is temperature sensitive so it is highly conforming to your body. Mattresses with memory foam can be all foam, have a coil unit or incorporate gel or latex.
Memory foam is measured by density. Normally, the minimum density of a quality memory foam is 3 pound. You can find memory foam mattresses at all price points, but be aware of the density and quality of the memory foam. The density of the foam has a direct impact on the long lasting comfort & durability of a memory foam mattress.
Gel Memory Foam
Gel memory foam is one of the newest innovations in sleep technology. Gel memory foam combines the benefits of traditional memory foam with the cooling effect of gel. Serta has a wide range of mattresses with gel-infused memory foam like their popular iComfort line and the new iComfort Directions line.