Single size in the UK equals two sizes. Either 2'6" / 76 cm or 3'0" / 90 cm are the widths and 6'3"/190 cm long.
These standard sizes are used for mattresses, beds and sofa beds.
Single futon mattresses have options for firmness and comfort subjective matters so are there for you to choose.
Single sofa beds are slatted and are to be used with either futon mattresses or a bed mattress.
We have developed a filling that includes a low profile pocket spring layer called flexi pocket. Since it is springy it is also softer as a result if that's what you prefer.
Another in house developed filling is a cotton/polyester blend. Baked to a temperature that gives a characteristic so it prevents compacting. This then helps the mattress to keep its shape and form.
An Upholstered Chair Bed called Cubed 90 cm is a European single size that has a slightly different standard length, 200 cm.