What does it mean for a magazine to eliminate cover lines, or reduce them to insignificance? It suggests that the magazine is confident of its readership in a way that few modern magazines can afford to be.
Although competition was extreme among some magazines, major magazines of this period gained a prominence with their readers that permitted them the luxury that by merely announcing their presence with a gorgeous cover, they would be read. Increased use of cover lines reflects the intensity of competition; the greater the competition--especially for newsstand sales-- the more intensely a magazine uses cover lines to attract readers.
By following the rise and subsequent decline of the poster cover, we can track the experiment in using illustrations alone (or primarily) as a means of attracting readers, and we can see how cover lines, which had made a powerful appearance around 1900, returned in the 1940s, and, by the 1960s, became elements of cover design in their own right.
It is impossible to generalize in a way that covers all variations, especially in a field as varied as magazines. But there was a powerful trend of using plentiful, dynamic cover lines on the covers of magazines in the early 1900s. Then magazine covers became dominated by poster covers for about 40 years. Our focus here is largely on the dominant, prestige magazines like the ones illustrated.
The covers of the non-prestige magazines--farm and trade journals, adventure magazines, and many others--continued to compete and innovate, using a wide variety of cover experiments. The adventure magazines, in particular, anticipated the alluring pictures, brash colors, and splashy cover lines of later decades. That history, however, will have to be told elsewhere.