A method of making mask structure including two or more masks for a mask-focusing colour picture tube and the mask structure formed by the method. A plurality of apertured flat masks, each mask comprising an effective portion having apertures and a border surrounding the effective portion are stacked with the apertures aligned, then filling material is poured into the apertures. The filling material is solidified thereby fixing the flat masks together. The fixed masks are pressed into a predetermined curved shape. Then, the filling material is removed from the apertures and the masks are separated.