Abstract: At least a pair of separate cushioning members are interconnected by an overlying face of a cover and disposed side by side at the side regions, border strips are secured each along one of their edges to a corresponding inner skin overlying one main face of a cushioning member, at the opposite main faces corresponding cover sheets are secured at the other edges of the border strips; the interconnecting cover overlies the inner skins and is secured along its periphery to them and to the first-mentioned edges of the border strips.The method includes joining two border strips each to one edge of an inner skin, drawing them round a cushioning member and securing a cover sheet to each, over laying an additional cover sheet over both skins and securing it peripherally to them and the adjacent edges of the border strips forming two pouches one to both sides of a hingeable fold zone of the overlying cover sheet.