Working at home over a period of 15 years, he devised techniques to build a good guitar. In ”Classical Guitar Construction,” in 1966, he outlined the steps. In ”Guitar Repair” (1973) he taught how to fix them. ”Steel String Guitar Construction” and ”Making Musical Instruments” were his final two books. Roger Sadowsky, a New York luthier who was a graduate student at the time, stumbled on ”Classical Guitar Construction” in The Whole Earth Catalogue. ”Reading it was like entering a new world,” he said. ”I can vividly recall the pictures of Irving planing his wood to thickness and boiling his sides in a galvanized pan.” The books, he said, started him on his career.