Barry, it's a full time job because if you think of a tree, the trunk is the subject and there are so many branches and roots which become side tracking, you tend to forget where you started! I Began studying some pews a few years ago and honestly ended up studying the production of shellac from India to Germany. I ended up in a total knot as I got deeper into turpentine medicinal qualities and timber technology of Northern Pitch Pine and Red Pine. You just have to know when to stop.