[OzEclipse (Joe Cali)]

Originally Posted by leon

The best printed photos have archival lifetimes estimated between 100-200 years for monochrome prints with Epson ultrachrome pigmented inks on archival papers or Giclee prints, nowhere near a million years.

That is true Joe, but if photos were never exposed to light and keep at a constant temp of some 3-4 meters underground surly we could expect a much longer period before any degrading.
I know a million is a fair stretch, so maybe half million.

Leon

Leon,
Light makes the dyes fade. You also need an oxygen free atmosphere to stop the oxidation of the paper base. Exposure to air will turn most paper brown over a period of hundreds of years.

Joe