When realistic adventure comic strips appeared in the newspapers, it was a big change from the line-dominated cartoon style that had prevailed until then.
One of the pioneers of adventure comics was Milton Caniff (1907-1988). Caniff used dramatic blacks, applied with a brush, providing an opportunity to sink some forms into silhouette, or present mysterious lighting effects. He took some of his inspiration from work he saw in book illustrations.
Milt Caniff's studio mate was Noel Sickles (1910-1982), who had drawn an adventure strip called Scorchy Smith. Sickles was always interested in dramatic, realistic storytelling. He showed Caniff "a set of illustrations by Harold Von Schmidt for Willa Cather's Death Comes for the Archbishop—employing lush black brushwork, defining objects by shadows as much as outlines—Sickles introduced ultra-realism and impressionistic linework to the comics." The quote is from America's Great Comic-Strip Artists, by Richard Marschall.
When Von Schmidt (1893-1982) undertook to illustrate the lavish 1929 edition of Cather's book, he took six months off his magazine illustration career and traveled to the American southwest to see the frontier settings of Cather's book. He produced over 60 black and white illustrations, using a brush and ink style where he grouped the cast shadows with the shadow side of the form to create mysterious shapes.
More examples of Von Schmidt's work at Jim V.'s Illustrators website
Death Comes for the Archbishop