Roof designs have varied widely and have evolved from the earliest models, where roofs were demountable and/or detachable. Contemporary roofs are often hinged to fold away, either into a recess behind the rear seats or into the boot or trunk of the vehicle. The roof may operate either manually or automatically via hydraulic or electrical actuators, and the roof itself may be constructed of soft or rigid material. Soft-tops are made of vinyl, canvas or other textile material, while hard-tops are made of steel, aluminum, plastic, or other rigid materials.