A tri-fold futon is a piece of furniture that is able to function as either a bed or a seating area by converting through two bend mechanisms. The dual nature of this type of futon is quite similar to other futons, though it has two folding locations rather than one. Since there are two joints on this type of futon, it creates three separate areas that change position, which gives the futon its name. A tri-fold futon can be designed in a number of different ways, though the mattress usually folds under the seat or over the back of the futon.
Sometimes called a Z-fold or Z futon, a tri-fold futon is often larger than other futons and can provide more options than bi-fold futons. A bi-fold futon typically has only a single bend mechanism, allowing the futon to fold once along the length of the futon. This allows the futon to fold up into a couch or to lie flat and act as a bed. While a tri-fold futon is fairly similar in shape and function to a standard futon, it features two bend mechanisms, which creates three planes and gives the futon its name.
The two mechanisms typically allows the futon to fold twice across the width of the futon, rather than along the length of the futon. This allows for a larger futon with a larger mattress to still be folded for use as a couch. A tri-fold futon usually has one mechanism that allows it to fold and create the two planes that act as a seat and back for the couch. The third area typically acts as a foot rest, creating a recliner, or folds under the seating area to create a couch.
When a tri-fold futon is folded into a couch shape, there are typically two different ways in which the mattress folds with it. One of the most common means is to have the excess mattress at the top of the couch and fold it over the back of the headrest. Other models can instead have the mattress folded under the seating portion to create a seat that is twice the thickness of the mattress. While this can be more comfortable for long sitting, it can also potentially wear down the mattress more quickly.