Many people mistaken body impression as sagging on the mattress. This is a misconception. If your mattress has a body impression or indentation of up to 1.5 inches, it does not consider as a defect. It is all well within the industrial tolerance limit. As mentioned earlier, body impression is formed due to the foams and fibers conforming to your body. This impression or indentation does not affect the support you have from your mattress. Sagging on the other hand, refers to inadequate support from the coil system, which make you feel like you are “sinking-in” when you lie on the mattress. Mattress which sagged is more obvious to the eyes.