Firstly, it is important for you to know that body impressions can occur in all mattresses, eventually.
Body Impressions are simply the settling and compression of the foams, fibre and fabrics in the upholstery layers of the mattress. These are going to be the most noticeable in the areas of the mattress where your body weight is compressing these layers.
Plush or soft mattresses in particular, can show noticeable body impressions within a short time of use. The fillings in a softer mattress will be loose so settling occurs more easily.
Firmer mattresses will have compressed fillings and denser foams so the settling may not be as noticeable.
This shouldn’t stop you from purchasing a softer mattress if this is what you need. I would always put comfort ahead of any other feature when I am choosing a mattress.
Funnily enough, very cheap mattresses tend to not suffer from Body Impressions because they simply don’t have much foam or fillings over the springs. Of course, this is not what you want. There is no point buying an uncomfortable mattress, regardless of how cheap it is.
In a perfect world, us mattress makers want you to sleep like a log in your new mattress. We want you lie down to sleep then not move for the next 6 – 10 hours, or however long your body needs to sleep.
If that’s the case, and since humans are creatures of habit, there’s a good chance that you will sleep in that same spot and that same position night after night. So, it’s in this area that the upholstery layers will compress the most.
The areas of your mattress that you are not using or sleeping on will remain in an uncompressed state.
If you and your partner are sleeping in a large bed such as a King size, you may start to notice that the middle area between you starts looking like a hump. But, this is just because this area is not being utilised.
Whenever you can, spend some time in these uncompressed areas. It may not be practical for two people to sleep in the centre of the bed but whenever there is just one person using the bed, they should spend as much times as possible in that centre section.
Rotate or turn your mattress regularly. There is no hard or fast rule as to how often you should do this but if you turn it every time you change your sheets then the mattress will compress at a more even rate.
Most Australian mattresses are single sided, so don’t flip these over thinking it will even out the fillings. The underside of a single sided mattress won’t be comfortable.
As the mattresses ages and you use more of the surface of the mattress, body impressions will become less noticeable. In fact, they can even disappear completely.
This is why we often hear “my old mattress didn’t have any body impressions”.
And lastly, Body Impressions may not be a fault in the mattress. As explained, they are simply a natural occurrence in new mattresses.
If you find that your new mattress is showing very distinctive 'dips' within a short period of time, it may be that the foam grades that have been used in the mattress are poor quality. This is why we encourage all mattress shoppers to try to find out the specifications in the mattress before purchasing. We have an article all about foam grades here and we publish our full specifications here so that you can easily judge for yourself how long the foams in a Sherman mattress will last.