Abstract: A cathode-ray tube of the vertical line screen, slit apertures mask type includes a mask wherein the horizontal curvature of the mask is made greater than that suggested by the prior art for similar type tubes. Because of the added curvature, the degree of electron beam misregister caused by mask doming is reduced. To obtain acceptable packing of the screen lines, the horizontal center-to-center spacing between adjacent apertures in the mask are varied in relation to the difference in mask-to-screen spacing with respect to the prior art. The additional mask curvature need not necessarily be in a single arch but also may take the form of parallel extending corrugations in the mask.