The futon sofa is typically called just a futon and is a mattress that makes up a Japanese bed. In Japan these sofas are sold in specialty stores and called futon-yas. The mattress itself is flat and measure about 5 centimeters in thickness. The fabric on the outside is stuffed with cotton or synthetic batting. In some department stores in Japan the futon is sold as a set with a mattress and a bedspread to match.
Traditional Japanese futons are designed to be placed on tatami flooring and can be folded and stored when not in use. Western futons are slightly different than the Japanese model. The idea behind the futon is the same but the design of western futons greatly differs from that of the Japanese model. These futons come with a mattress and frame on which the mattress is placed.
They serve a dual purpose in a room as a bed and sofa. The frame can be folded out so that it serves as a bed and during the day it can be folded back into the sofa position, which allows people to sit on it. The mattresses of futons are filled with foam as well as batting. More modern mattresses for futons are almost the same size as a regular mattress.
Western futons are being used as sofas more and more often due to the fact that they offer people a cheap alternative to an expensive sofa. They are also great for small spaces when a bed and sofa would take up too much room. Many people have a futon in their rec room so that they have a sofa that can double as an extra bed when they have company visiting and staying the night.
Using a futon as a bed and a sofa saves a great deal of room. Futons are usually sold as a set that includes the frame and the mattress. New or additional mattresses can be purchased separately from the frame if needed but this could become expensive.