One of the best sources for this is Wilhelm Imaging Research (www.wilhelm-research.com), an independent organization that does exhaustive tests for lightfastness on printers, inks and papers. It provides extensive data on print life, using specific printers with a wide variety of papers.
When it comes to longevity, it's essential to understand the types of papers that are available for inkjet printers. Three common types include swellable, porous and cotton rag.
Swellable papers consist of three separate layers, two of which are polyethylene. Between these two layers is the paper base that absorbs the ink. This type of paper is best suited for dye-based printers, despite some papers being marketed as "universal," meaning compatible with pigment-based printers, which they often are not.
"A swellable paper is a paper that literally swells in the presence of moisture," says Dan Steinhardt, marketing manager for Epson America. "The ink is absorbed into the swellable layer. The problem with swellable papers is that they're highly susceptible at all times to moisture, not just from ink. It especially becomes an issue for those living in high-humidity environments."
As the name suggests, porous papers consist of spaces where ink is deposited. One of the benefits of their special coating is faster drying time and a higher resistance to damage from moisture and humidity, as well as other pollutants. Typically, porous papers deliver better results, in terms of lightfastness, with pigment-based inks than with dye-based inks.
"A porous paper has many microscopic holes so that the ink can penetrate," says Steinhardt. "They're also known as instant dry papers. They tend to also be resin-coated papers such as Epson's Premium Luster paper. The advantage of such papers is that you can use either dye-based or pigment-based inks—both are compatible."