I submitted this after doing some research about the impermanence of in jet inks but a deeper search revealed that this is an ongoing problem and most companies involved in computer printing are very aware of the problem. Laser jet is more permanent but there are problems with the pigments melting and migrating under heat encountered during an ordinary summer. Sealing the surface might help to a certain extent but ultra-violet light becomes a factor and I don't know if sealants are available that block ultra-violet. Perhaps laser burning the paper surface itself to create the print might work but that would be only for black and white, no color. Dye colors seem the most vulnerable and I don't know much about pigment based printing.

The longest-lasting film negatives are those based on silver chemistry; you may get longer-lasting images by printing different images for each color, photographing them individually with traditional B&W film chemistry- this would give four B&W film negatives for each color image (red, yellow, blue, and black). In fact, this is old tech, magazines have been doing this for over a century.