materials best for impermanence

[The Hat]

@fader, The only way I can see this working out satisfactory is for you to get the desired fading effects in Photoshop first, then give your image to someone with a pigment printer and you’ll have a permanent faded printed image that you can then sell commercially, the only outlay will be for the Photoshop App...
A dye ink faded image won’t stop fading..

 

[Smile]

If this is science related I can understand, else OP has too much free time.

 

[PeterBJ]

It is science/education related. In the first post the OP wrote:

For my diploma work at an art university (please don`t stop reading now), I experiment with print (im)permanence. I`m glad that I have found this forum, especially the thread "Papers to minimise fade with aftermarket dye inks." which include impressive fading and color shift tests, exactly what I have searched for more then a year (but did not completely answered my question).

 

[Smile]

Well that explains it, it's not commercial project then.