and 52 terminate respectively and that the depth or difference in elevation as viewed in fig7 between the high and low points is substantial when measured with respect to any convenient reference line such as a linear reference line which lies in the plane of the cut as will be noted from fig9 the shade may have high points and low points in the direction of the drop of the shade as well as the direction of the width as illustrated in fig6 and 8 in fig9 and 10 a rather substantial depression is formed in the sheet member as a result of a major rib 45 the exterior surface of the sheet member including a rather deep impression indicated at 46 the cut lines referred to above are illustrated best in fig7 and 9 referring first to fig7 the sheet member is indicated in its condition prior to the stripping to width operation illustrated in fig2 a series of cut lines 48 49 50 51 52 53 54 and 55 are formed in the body of the sheet member adjacent one side here right side edge 56 it will be noted that cut lines 48 55 are straight and parallel to one another and right side edge 56.