Abstract: A foldable springless mattress for a sleeper sofa has a hard but bendable bottom insulator pad, a first flexible foam layer adhered on top of the insulator pad, an all-natural latex rubber layer adhered on top of the first flexible foam layer, and a composite panel adhered on top of the rubber layer. The composite panel includes an intermediate layer of antimicrobial-treated fibers quilted together with a second flexible foam layer and a moisture-resistant damask fabric. This damask fabric covers all surfaces of the mattress. A process of making the foldable springless mattress includes the steps of providing the insulator pad, adhering the first flexible foam layer on top of the pad, adhering the rubber layer on top of the first flexible foam layer, and adhering the composite panel on top of the rubber layer. The composite panel is formed preliminarily by quilting the layer of antimicrobial-treated fibers together with the second flexible foam layer and the damask fabric.