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Old 09-12-2020, 10:10 PM
steve B steve B is offline
Steve Birmingham
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Join Date: Sep 2009
Location: eastern Mass.
Posts: 8,087
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Sounds like an interesting approach.

To the human eye, the inking levels of overlapping halftone dots can change the perceived color. slight registration problems can do the same thing.

It's interesting in many ways with your description of how surface defects are identified.
I take it you can pick up the depth of a stamping from how the pixel colors change around the edge of the stamping where the cardstock is curved. It will be curved for a larger distance if the stamping is deeper.

The gloss differences on 93 UD are tricky in anything but raking light.

I can think of a lot of other issues on modern cards that could be challenging at first.
(81 star stickers with black printed under a lighter blue on the front. Many 70's-80's sets that have both light and dark ink on the back. 88 score where both fronts and backs are screened differently, and have different die cuts so the corners are different.

Plus a few where the computer might be a huge help.
81 Topps low contrast backs (I have a bunch set aside, but I'm on the fence about them being truly different and whether the cause is different plate exposure, plate wear, or something else entirely.
Most Topps A+G and Gypsy Queen, I have many set aside as slightly tinted backs, compared to pure white backs. It's very subtle, and I have trouble picking them out if the lighting isn't right.

Hundreds of cards in each set from the 70's to 91 have recurring semi random spots. I have a bunch of these in my 81Topps list, and with only about 15-20000 cards looked through I'm sure I missed at least as many as I found. Cataloging them all so they aren't counted as surface defects would be amazing, but probably a pretty serious challenge.

I'd really love to know more about just how all this works. (But 1- I probably wouldn't understand some of it especially any math 2- I figure the exact details are probably being kept secret. ) My wife is a software developer, and we've talked about what would be easy and what would be hard a few times. I've often been surprised that some of what I think would be hard is something she thinks is no problem.
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