Having built quite a few guitars and working on some of my older ones, I have found that if you put the guitar front or back under intense fluorescent lighting, some will show slight, straight lines in the finish that you cannot feel or see in less intense light. It looks like evenly spaced lines in the body of the guitar or in the finish itself. These seem to run from the heel of the guitar to the top end of the body. I have found it on several of my guitars and even tried to polish it out on one of them, but to no avail. It looks like the joining of multiple pieces of wood bonded together to make one wider, flat surface, but that would make no sense for as narrow as each strip would be (about 1/2"). It is more of a curiosity than a problem because of its minimal visibility, but I am curious as to what I am actually seeing. Has anyone else ever seen this?