When there are many parts with clear quality differences, our catalog divides them by quality (Economy, Daily Driver, High Performance, or Copper, Platinum, Iridium). You can read Tom's latest article in Country Life 'The art of planting fine trees'??on our??Press Page. In many areas I have taught myself when an education was not available, but using the elements and principles as always kept me on course so that I don't stray when learning a new arena of design.