what do they mean by "nearly imperceptable"? 0

[Gabriel Contreras]

I just had a thought. In another forum a book was submitted PGM and the owner mentioned that the book he posted seems to look much worse than in person. We upload scans for grading and depending on your scanner settings "artifact" defects appear that would not normally appear with the naked eye . After all we read the books at about less than a foot away and that's how it was intended to present and be read at. . Many times I have seen my book uploaded with ghost text coming through the front from the backside print because of thin and cheap paper, or a staple about an inch in size? dust particles that would not be seen normally. Shouldn't a book be judged by the naked eye ? Or do graders use a magnifying glass? help because I really do not know.  At what point is it graded at the size it was originally intended to be viewed at (a bit less than 30" away) and now the perceptable   realistic

[Terrapin]

Not exactly sure what your question is but books aren't graded based on artifacts from scans or photos. A nearly imperceptible defect is still a defect although one which would not be noted upon a casual view. These are what separate the very high end grades. A small non color breaking stress line can be seen with the naked eye but unless you are really looking carefully it can be missed with a casual inspection. This is the reason so many think they have a 9.6/9.8 book when in reality it is quite a few grades lower.