He is known for his stylish images of women and a signature use of negative space in the paintings he created for advertisements and the covers of popular magazines.
In May 1908, he created a cover for the magazine that featured his first "fadeaway girl" design with a figure whose clothing matched, and disappeared into, the background.
Phillips's use of negative space allowed the viewer to "fill-in" the image; it also reduced printing costs for the magazine, as "the novelty of the technique and the striking design qualities masked the fact that Life was getting by with single color or two-color covers in a day when full-color covers were de rigueur for the better magazines".
[8] Phillips also created many advertising images for makers of women's clothing, and for such clients as the Overland automobile company and Oneida Community flatware.
[12] In 1924 he was diagnosed with tuberculosis of the kidney (Renal TB), and for the remainder of his life he was frequently ill.[13] In January 1927, when problems with his eyesight made painting difficult, he dedicated himself to writing.
In 2002, the Swann Gallery's “American Beauties: Drawings from the Golden Age of Illustration,” featured Phillips, Charles Dana Gibson, Wladyslaw Benda, and Nell Brinkley, among others.
[17] Phillips was also included in the Norman Rockwell Museum's "Toast of the Town: Norman Rockwell and the Artists of New Rochelle," and in "Illustrating Modern Life: The Golden Age of American Illustration from the Kelly Collection” at the Frederick R. Weisman Museum of Art at Pepperdine University.