An image receptor surface which receives an image of a sublimation dye thermally transferred thereto from a foundation sheet for formation of the image therein, the image receptor surface comprising a thermochromatic layer. The thermochromatic layer is a layer of a thermochromatic ink, and contains at least either one of an epoxy resin and an epoxy acrylate resin. The thermochromatic layer reversibly changes its color between an image concealable color and transparence in a predetermined temperature range. The image receptor surface may be formed of any of various materials or articles such as metals, wood materials, glass materials, ceramics, plastics, fabrics and fibrous materials for any applications, especially a mug.