An improved color picture tube includes a mask that has an aperture array including slit-shaped apertures aligned in columns that essentially parallel the minor axis and end at a border of the aperture array. Adjacent apertures in each column are separated by tie bars in the mask. The tie bars in one column are offset in the longitudinal direction, paralleling the minor axis, from the tie bars in each adjacent column. The spacing between tie bars in a column is the tie bar pitch at a location on the mask. A first set of columns, that includes every other column, has increased tie bar pitch at the ultimate end apertures, as compared to the tie bar pitch at the penultimate apertures in each of the columns. In a second set of columns, every other column not in the first set, has decreased tie bar pitch at the ultimate end apertures, as compared to the tie bar pitch at the penultimate apertures in each of the columns. The last tie bars before the ends of the aperture columns in the second set are shorter than the next to the last tie bars, measured in the longitudinal direction of the columns, and the ultimate apertures at the ends of all of the aperture columns end on a smooth border line.