loose cover

A slipcover (also called loose cover) is a fitted protective cover that may be slipped off and onto a piece of upholstered furniture. Slipcovers are usually made of cloth. Slipcovers slip on and off; they come fresh and may be removed for seasonal change, cleaning, moving, or storage.
Slipcovers are sometimes defined as "clothing for furniture." Indeed, they are tailored just as clothing and fitted loosely or snugly to the owner's or tailor's taste. Some order furniture upholstered in plain muslin, intending to use slipcovers only.

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