When shopping for a mattress for a platform bed, there are a few things consumers should consider. First, the way a mattress feels when you try it in the store is partly due to its matching foundation (box spring) – they are engineered to work in tandem with one another. When you replace the foundation with a platform bed's rigid surface, the feel will be different – generally, firmer and less resilient. You might also want to consult with your salesperson to determine if there are any changes in warranty coverage for a mattress used without its matching foundation.

INNERSPRING. The most widely purchased type of bedding uses the support of tempered steel coils in a variety of configurations. Layers of upholstery provide insulation and cushioning between your body and the spring unit. The result of this basic approach, coupled with state-of-the-art technology, is a full range of comfort choices.
Quality tip: You can't judge the quality of a mattress solely on the number of coils it contains. A high coil count doesn't automatically mean it's a better product. It's a combination of top quality innerspring system and superior upholstery materials that makes the difference.
FOAM. Solid foam mattresses also offer a wide choice of "feels". They can be made of a solid core or of several layers of different types of foam laminated together. Advanced technology in polyurethane foams, refinements to traditional latex foams and the new viscoelastic foams have added to the choice of comfort, support and performance.
FOUNDATION. A good foundation (box spring) is as important as a good mattress. Don't put a new mattress on an old foundation. When you select the mattress, purchase its companion foundation—the two are designed to work best together. In fact, buying the mattress without its matching foundation may affect the terms of the warranty.
Don't Forget The Pillow. Just as your bed should provide good support for your body, your pillow should give you the right cushioning to position your head and neck properly. It should hold your head in the same relation to your shoulders and spine as if you were standing with correct upright posture. If you sleep on your side, you may want a fairly firm pillow to give your head and neck extra support. If you sleep on your back, try a medium-firm pillow to cradle your head with more "give". And if you sleep on your stomach (although some physicians caution against this position), choose a soft pillow to lessen the strain on your neck.

Other Choices
AIRBEDS. Airbeds are now designed to look like the familiar mattress/box spring combination, with an air-filled core providing the support instead of an innerspring unit or foam core. These designs also offer a range of feels and typically are adjustable to suit individual sleepers' needs.
FUTONS. Futons are a popular alternative for those who need a sofa by day and a mattress by night. The mattresses must be very flexible, so they are typically made of cotton, synthetic fibers and foam in various combinations. The futon is designed to support sitting as well as sleeping.
ADJUSTABLE BEDS. Electrically adjustable beds allow sleepers to adjust the head and foot of the bed to the most comfortable position. The mattress and foundation must be specially built for the flexing motion and can be innerspring, foam or a combination. Since the flexing causes extra wear on the mattress, quality construction is very important. Mattresses not built for this purpose should not be used with an adjustable bed frame.
WATERBEDS. The newest waterbed designs are also built to look like the familiar mattress/foundation, with a water-filled core providing the support and layers of upholstery for insulation and surface comfort. Quality construction is especially critical when water is involved, so look for assurance that the vinyl and seaming are designed for maximum durability.