Method of manufacturing foamed product with skin and method of manufacturing said skin

A method of manufacturing a skin for foamed product involves the steps of: (a) not only preparing a plurality of flat skin forming pieces 2 to 5 by defining a skin 13 for covering an annular foamed body Y into a plurality of skins in radial directions and flatly developing the thus defined skins 131 to 134 while cutting apart at a single position along a circumference, and forming an opening 2a on a single skin surface out of these flat skin forming pieces; (b) overlapping adjacent flat skin forming pieces in such a manner that decorated surfaces of the skin forming pieces confront each other to thereby form a skin body 6 while joining side edges of the flat skin forming pieces 2 to 5 together; and (c) reversing the skin body 6 so that the front side thereof faces outward, joining diametrically opposite portions of both opening end edges of the skin body after such opening end edges have been pulled out of the opening 2a inside out, and pushing the joined opposite portions back through the opening 2a to thereby form an annular skin body 7 having a closed cross section with the front side thereof facing outward.