Herculaneum scrolls buried by Vesuvius yield another secret: metallic

[Viggen]

Using the world’s largest and most sophisticated x-ray microscope, scientists have read a little deeper into one of the iconic relics of the ancient world: a library of charred scrolls that survived the eruption of Mount Vesuvius almost 2000 years ago.  Last year, researchers managed to decipher some of the letters on the carbonised papyri. Now, unexpectedly, they reveal in the Proceedings of the National Academy of Sciences that they have established that the scribes who copied the ancient texts knew the secret of metallic ink.

 

via the Guardian

[caesar novus]

knew the secret of metallic ink.

 

I wonder what is the secret of metallic ink. I had read this before, and can only gather that it will aid us reading faint text. But why was it so great for the Romans themselves?

 

Maybe the soot ink smeared too much? Someone invented non-smeary newspaper ink about 20 years ago but could not sell it because it cost a tiny bit more. Another current problem is fading ink... if you look at some receipts a decade or so old, you may notice the printer ink is fading to nothingness, and will not serve their purpose for taxes or whatever.