Yesterday ... I was wondering, whether it is possible to remove old permanent marker defacings (done with a waterproof "Edding" in this case) from some 30- year-old photo negatives ... (yes, I hated myself back then and those photos, too) … without completely destroying the negatives in the process.
 
I couldn't find an answer to this particular question on the internet, only learned that

isopropanol alcohol

and

distilled water

are generally considered of great help, when trying to clean "dirt" (in the widest sense) off said objects.
 
I then sent a question regarding this matter to Edding's customer service, and though their reply came swiftly, they didn't have an answer either, as they said, they have no experience with this exact problem. However, they also mentioned isopropanol alcohol, which, they promised, works great for getting rid of their waterproof Edding from non-porous surfaces.
 
So ... I tried it.
 
At first, nothing really happened.
 
But then I discovered, when you go back and forth between the alcohol and the distilled water (as in soak and carefully scrub the negative in the alcohol, then rinse everything off in the water, then go back to the alcohol … and so on), the marker eventually really comes off.
 
Now, mind you, it is quite possible that - over time - this method may completely dissolve the negative. I don't know. We'll see.
 
Speaking of seeing … since my brain has trouble correctly interpreting negatives, I inverted the photo I took of that one negative (which is from 1995/6, I believe) on my computer, and there I noticed that traces of the permanent marker are still visible.
 
It may or may not be possible to completely remove those stripes by repeating this cleaning process a few more times, but, honestly, I really cannot be bothered.
 
I am fine with these minor imperfections. They are like scars. They tell a story.