A futon mattress is usually a great choice for many homes; not only can they be used as a general mattress (depending on the thickness), they can be used as a couch or even just a guest bed.
However, buying a futon mattress is more complicated and requires you to decide which functions and qualities best suit your needs.
The futon mattress originate from Japan and traditionally, they are not used with frames.
They are anywhere between 2 to 4 inches thick and provide decent body support.
If you are going to be using the futon mattresses for sleeping then the best choice is to get a thick/heavy futon.
Understand that light ones are still comfortable and quite useful for guests.
The next function when looking for any mattress is firmness.
Everyone requires different back support so too much detail cannot be used.
However being too firm is definitely not good, and while being very soft can be quite relaxing at first, it can turn very uncomfortable when sleeping for an excess of 3 hours.
Flexibility is another one which should be considered whenever you are buying a futon.
This refers to how easily (or difficult) it is to fold a mattress.
One thing to note is that a futon mattress can be bi-fold (can be folded twice) or tri-fold (can be folded three times), and that this can be quite annoying when trying to fold it every morning, so bear this in mind as well.
Although traditionally, these were just placed on top of tatami mats (woven mats - effectively the floor), many of us will still require the use of a frame.
It is better to use a wooden frame because it is usually more durable and has a more quality feel to it.
However depending on the actual wood, it can be rather expensive.
The material is the next thing to decide upon.
It is usually staple cotton and that is fine if you have enough money.
If you don't then it will be a better idea use a substitute.
Understand that you are going to sleep a third of your life so you should try and make that time as comfortable as possible.