The mattress information below I received at work yesterday through our wellness department. I found it interesting as I never really knew how to buy a mattress. Mine is 9 years old so this is good info to know. I also have an eggcrate on my bed I really like by Isotonic. I bought it with my 20% off one item Bed Bath and Beyond coupon I get in snail mail.
http://www.bedbathandbeyond.com/product.asp?order_num=-1&SKU=113127
"We all know how important it is to get our 7-8 hours of sweet slumber each night. For many of us, the quality of our mattress is directly related to how well we snooze. If you go into a mattress store these days you may be overwhelmed with the choices! One of the secrets to assessing a good quality mattress is coil gauge. Most of the mattress's support comes from its springs, which are made of wire. The thickness of the wire determines how much each spring will "give" when you put pressure on it. The gauges or thickness range from 12.5 (very thick) to 18 (thin). Generally, high quality mattresses use 14-gauge wire. Another key is coil count. A good full size mattress has at least 300 coils; a queen 375 and 450 for a king.These are the minimum number of coils needed to prevent sagging. So if you are shopping for a new mattress perhaps these tips will put you one step closer to better slumber. Happy Zzzzzzzzzzzzzz.............'s."
11 years ago