John Prentice spent his childhood in Texas. During World War II, he was in the Navy, where he partipated in the battles in Guadalcanal, Midway, Iwo Jima and Okinawa. After a six-year term in the Navy, Prentice went to the Art Institute of Pittsburgh. Soon he did his first artistic efforts, in lay-out, design work, and advertising illustration. He also helped produce some comic books, penciling and inking comics by National and the Ziff-Davis Studios, mostly through the Kirby-Simon studio.
After the death of Alex Raymond in 1956, Prentice was asked to continue the 'Rip Kirby' strip. Prentice agreed, and got the assistance of Fred Dickinson, who did the continuity for the series. Prentice drew the strip fro 43 years and retained Raymond's 'Rip Kirby' style, adding only subtle changes.