I have a client possibly interested in purchasing several 40x65 prints from me done with PiezoPro inks on Hahnemuhle Photo Rag 188, and she asked me how long the prints will last. The prints would be installed in a large lobby with many floor to ceiling windows, so I assume bright illumination but not direct sunlight.
When I look on the Aardenburg site, the only carbon/selenium inks sets I see are called Piezotone from 2009. On a 9800 the Aardenburgh test indicate Piezotone inks have a display rating of 88 Megalux hours or approximately 44 years in an average bright room.
Are Piezography Pro inks the same as the tested Piezotone from 2009? Should I expect them to have the same fade characteristics?
I print on the slight cool side with the Piezography inks. Should I then expect less of a density change and more of a color shift toward the warm carbon color over years of exposure?
Aardenburg did not test the Piezography Pro inks as none of our customers submitted for tests and he would not allow us to submit considering us to be an OEM. But they are not similar to Piezography Carbon K7 which is a 100% carbon ink. Piezography Pro is a combination of carbon and color pigment so would be more similar in longevity to ABW tests submitted.
EPSON ABW is a method printing black and white with EPSON carbon light blacks and color pigments. So while we may use more carbon than EPSON it is still more a comparative than the earlier Piezography K7 inks. Incidentally, we are still supplying Piezography Carbon K7 which is the ink that Aardenburg wrote is unaffected by light. It’s the only 100% pure carbon ink available.
Longevity in terms of fade resistance is directly proportional and more importantly relative to how long a photograph is going to be on constant display in harsh lighting. Most photographs hanging in brightly lit atriums (as an example) are subject to building ownership changes as well as administration staff changes which in the course of business result in works being exchanged quite frequently and therefore the likelihood of a photograph being continuously displayed in one of these harsh environments for 400 years is as unlikely as it might be for even just 1-5 years. Very few works of photography are exhibited in harsh light for more than just a few months or years even as they should not be.
Any of the Piezography inks are capable of withstanding normal continuous display in an art context for a century or longer. However, no one knows if the fine art inkjet papers being used will last that long because no archival testing takes place with papers just a study of how the inkjet coating affects fading in the prints due to how the inks interact and mix when first printed.
The reality is that most photographs spend their lives in drawers or archival storage boxes rather than on continuous display unless perhaps it is a portrait of the Pope in the Hall of Popes. These are never exchanged or replaced.
Honestly, I think your more serious concern is what you print on. Uncoated 100% cotton, lignin and acid-free papers or uncoated washi would be what you should be printing on if longevity is your biggest concern. But most definitely not on papers with a hydroscopic inkjet coating. You give up acuity and dMax on these papers, but they are known to have very long life-spans and are inert - whereas inkjet coatings continuously interact with the atmosphere.