His technical skill with lithography remains a standard for the medium. Dehn manipulated the stone with unconventional tools to create soft, atmospheric effects. He used sandpaper and razor blades to scrape away ink. This produced a range of grey tones that mimicked watercolour washes. His work shifted from biting social caricatures to expansive views of the American countryside. These later pieces focus on the geometry of hills and the weight of clouds over the Midwest.

Modern collectors value Dehn for his ability to balance graphic precision with a sense of space. His prints offer a calm, observational quality that suits contemporary interiors. The monochromatic palette of his lithographs provides a subtle alternative to more colourful works. His depictions of New York City and the Great Plains remain relevant because they avoid sentimentality. Instead, they present a clear-eyed view of the world as it appeared in the mid-twentieth century.