Did some test prints about 5 years ago (September 2010) using Ink Jet Printer. Prints was stored inside room without album and with minor expose to sunlight. There is an adhesive tape on a left bottom corner of each photo. To see how impact light compare to air contact. Also top left corner was immersed in water.
Printed using: Canon PIXMA iP1900.
5 Years old prints:
Print on HP Premium Premium Plus photo paper. 0.40 $
Print on Canon Photo Paper Plus II (PP-201) 0.24$
Print on Canon Photo Pro (PR-101) ~ 1$ (not available now)
Print on Canon Photo Pro Plus II (PR-201) ~ 1$ (not available now)
Need to mention that HP Everyday photopaper (not participating in test) was faiding out like that in about 6 months.
others less expensive