Most mattress toppers are made from either memory foam, traditional foam, natural latex or wool.Memory Foam mattress overlaysThese toppers are made from polyurethane, with a different cell structure from traditional foam. This cell structure makes it less 'springy' and slower to recover (hence 'memory foam' it 'remembers' your shape for a while after you've moved).Sensitive to weight and temperature, it moulds to your body's form, supporting it evenly, rather than having pressure concentrate at the shoulders, hips and feet. They're used in some hospitals and nursing homes to help prevent pressure ulcers caused by lying in one position for a long time.It takes about 15 minutes for the foam to fully warm up and soften, so what feels pleasantly firm at first (or unpleasantly hard) may not stay that way for long.Traditional foam mattress overlaysThe resilience of our Traditional Foam Toppers provides luxurious comfort and plush support.Natural Latex overlaysLatex comes from the rubber tree, and is naturally durable and resilient. Another advantage is that it is naturally hypoallergenic. It has only one drawback - cost. A good quality latex topper can cost as much as a cheap mattress.It is also important to keep in mind that by it's nature, latex can have various cosmetic imperfections, small tears, and/or discolorations, none of which will affect its performance.Woolen overlaysInitially sleeping on a wool mattress pads is like sleeping on a big sheep skin, soft comfortable and with all the advantages of wool. Unfortunately over time they tend to matt down, becoming flat and offering little in the way of softness.