I own a number of technical books on painting. They are all interesting and useful, but there is one that is truly indispensable: Formulas for Painters, by Robert Massey. It is clear, concise, well-organized and impeccably researched. My copy is a third edition paperback, printed in 1979. I found it in a studio locker at Scripps College when I was an undergraduate Studio Art major. It is inscribed "For Amy, 3/10/83," though it was meant for another Amy, not for me. I reasoned that, since the Amy for whom it was intended seemed to have misplaced it, I would keep it. It WAS meant for me. Since then, it has been a constant companion in the studio. I have recommended it to hundreds of students over the years.