A Mattress top is a usually a 2 to 3 inch piece of foam that is the same size as your mattress that you lay on top of your regular mattress to provide a more comfortable nights sleep. There are a variety of foams used for these mattress tops but the most popular type of foam is what is known as memory foam. Although different companies make their own version of memory foam they should all have certain features in common.

The main two features that make memory foam mattress toppers different from other mattress tops is that this material fits to the contours of your body lending support to areas such as your lower back, neck and behind the knee area. It also springs back into shape when all weight is removed from it.

 

It does not matter which way you lay it on the frame unless the style you bought specifically has a top and bottom. See if there is a certain design pattern on one side of the mattress to determine which side is top.