An improved color picture tube includes a shadow mask and a dot screen, wherein the mask is rectangular and has two horizontal long sides and two vertical short sides. The long sides parallel a central major axis of the mask and the short sides parallel a central minor axis of the mask. The mask includes an array of apertures arranged in vertical columns and horizontal rows. Apertures in one row are in different columns than are the apertures in adjacent rows. The vertical spacing between apertures in the same column is the vertical pitch of the apertures and the horizontal spacing between apertures in the same row is the horizontal pitch of the apertures. The improvement includes the horizontal pitch of the apertures increasing from the minor axis to the short sides of the mask and decreasing from the major axis to the long sides of the mask. Also, along the major axis, the vertical pitch of the mask decreases from the center to the short sides of the mask and, adjacent the long sides of the mask, it increases from the minor axis to the corners of the mask.