I discovered something earlier while cleaning up after a platinum printing session.

I usually fire up my UV box just to check it before I put it away, while doing so in the dark, ambient UV from the box hit a few 8x10 negatives on a table nearby then I noticed something odd, all my negatives had weird markings.

And so I decided to place some of these negatives on inside my UV box and lo and behold—they all have the same marks (see attached) only visible under UV light. These markings are neither visible with the naked eye nor do they show up in scans.

This explains a test print I did a month ago that displayed some odd blotches (see attached) which I just shrugged off.

Any ideas what these might be?

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