A resealable flap device in the form of a sheet, for applying to or incorporating in packaging, comprises: a lower layer of flexible material, and an upper layer of stiff material. The sheet is cut through both layers to outline a flap portion, the cut leaving an edge in a hinge region, the upper layer being removed behind the line of the hinge region. In this way the flexible lower layer forms a hinge that is easy to handle and does not spring back, while the stiff upper layer maintains the shape of the flap.