As best I can tell, Ratterman was a skilled illustrator, but not quite the equal of top-rank contemporary 1920s and early 1930s practitioners such as Dean Cornwell and Mead Schaeffer.
Examples of his work are lacking on the Internet, but some are displayed below.
Story illustration typical of the kind seen in those days -- nothing special about it.
On the other hand, this earlier work has some merit, though it too is not unusual or exceptional.
Probably from the early-mid 1930s: the women are nicely depicted.
From about the same time as the previous image. Something seems wrong about the area of the featured woman's hips. Otherwise, a competently done illustration.
I like this one, and wish it were available in larger size.
An example of the then-popular vignette style, but here for an advertisement rather than as a story illustration.
From around 1936. More vignette, but I don't know if it was a commercial work or a painting done for Ratterman's use or for a friend.