... I would suggest that important as longevity is, we shouldn't be making these important purchase decisions unidimensionally.
Today's market reality is that print longevity is almost always at the bottom of the "features" list when folks choose a new inkjet printer. People buy modern inkjet printers first and foremost on some calculus of immediate value to them, ie., price, perceived reliability, popularity, size and weight, and so forth. Print permanence is almost always at the bottom of the "desired features" list and confounded by simple assertions that all printer and media manufacturers are more than willing to endorse., e.g., "all pigment ink sets are archival", all "acid-free, lignin-free papers are archival", yada, yada, never mind the actual ink chemistry, drop size, screening, and channel blending printer driver algorithms, ink receptor coating properties, and media yellowing characteristics all contribute to the print permanence outcome. The truth is far more complex. That's why printer,ink, and paper compatibility studies are useful.
My prediction based on today's current aqueous pigmented inkjet ink performance: Media, not ink, is going to be the next battleground for print permanence claims.Lost in the embarrassingly naive "how long does it last" discussion of print permanence is the very real manifestation of aging as an equation of state, ie., what is the condition of the print at any point in time along its journey from brand new to very very old. All art and antiquity appraisers understand that it's the authorship, rarity, and current visual/physical condition of the object that counts, because all man-made objects exist in various states of deterioration at various points in time. For families with vintage family photos in their possession, it becomes even simpler than that. Does the print still have sentimental value? If so, it's worth keeping, no matter how bad it looks, yet prints in good condition always convey the original intent of the work better than prints in poorer condition.
regards,
Mark
http://www.aardenburg-imaging.com