Due to Priest's color-blindness, his primary medium was pen and ink, which he put to great use in inexpensively printed, highly graphic, rock posters.
Often printed in single color or split-fountain reliefs, the posters were done mostly for Armadillo World Headquarters, a music hall in Austin, Texas that operated from August 7, 1970 to December 31, 1980.
He worked with artist Jim Franklin and took over as art director after cartoonist Gilbert Shelton moved to San Francisco to become a key member of the underground comix movement.
"The Armadillo Art Squad," with Priest as its most prominent member, included artists Michael E. Arth [de; es; fr; ja; zh], Kerry Awn, Guy Juke, Ken Featherston, Jim Franklin, Danny Garrett, Henry Gonzales, Bill Narum, Dale Wilkins, and Sam Yeates.
The city and the state it capitalized; citizens of all stripes and denizens of cafes, bars and clubs; the countryside and its critters; the music and the musicians – especially these – were all grist for his mill.