None, I keep em on my bookshelf. I refer to my design books. My favorite of all time, is "The Nature and Art of Workmanship" by David Pye, given to me by a for

None, I keep em on my bookshelf. I refer to my design books. My favorite of all time, is "The Nature and Art of Workmanship" by David Pye, given to me by a former woodturning mentor.