My perception is that the production of romantic postcards (“fantasies” as they are called in France) slowed after 1910 and was interrupted by WWI. At least, for what it is worth, I have essentially not found any French postcards in the style dated between 1910-1920 (I’d love to hear from anyone with a different perspective). In the 1920s, there emerged a style of highly colorized and lushly romantic postcards. In sharp contrast to the famous singers/actresses featured on the earlier cards, the models on these cards are anonymous. Here is a set of cards featuring couples; there are also similar cards featuring women on their own (in that sense more like the earlier cards). The postcards on this page are from three studios: Noyer, P.C., and Bleuet.
1920s Colorized Romantic Postcards