All my newer prints are produced on my own equipment in-house. I use an inkjet system with pigment based ink (inkjet printers usually use dye-based ink, which is not colourfast). All prints are on 251 gram semi-gloss paper and the manufacturer guarantees the ink against fading under normal conditions for 85 years. These new prints are every bit as good as the lithographs I have had in the past.
My older prints are lithographs on 275 gram matt art board.