This charming Modess sanitary napkin ad is from the October 1940 issue of Woman’s Home Companion magazine. It was likely at the start of their long-running advertising campaign of using elegantly dressed models and subsequent “Modess…because” tag line.
This ad uses “Soft as a fleecy cloud” caption, with emphasis put on the comfort and security of the napkin. Sanitary napkins were relatively new on the market, and they tried to show how you could dress nicely and be protected. I’m sure it was revolutionary for women as the most commonly used napkins, up until then, were cloth rags that you had to wash.