Kodak states for the new Professional Gold DVD-R media: "Kodak professional discs have been tested under light and accelerated aging to preserve 200 years with proper handling." http://www.alkemy.eu/gold_professional_dvd.html
MPO (France) make gold DVD-R and DVD+R for libraries and archives. http://www.mpo.fr/documents/catalogue/gamme_dvdr.pdf
Richard ( a generally happy user of MAM-A products in Plexwriter drives)