I gave away some drawings some fourteen months ago, and now I've seen them again, and they've faded badly. I can't rule out the paper in the equation, but I've given up on the Artline Ergoline felt-tips that I used for them, and which I otherwise liked. (I am using acid-free paper exclusively now).
So, I'm looking for suggestions for "archival-grade" felt-tips / fine-liners. What am I looking for if I want my drawings to last as long as possible? Any good references or books on the different inks (pigment, dye)?
I've tried acceptable pens (in terms of line quality, "action", feel, etc) from Artline, Pilot and Staedtler. I liked the Artline the most and the Staedtler the least.
Also, I sometime use Copic markers to fill in larger areas with black or to shade with gray. Will these fade?
What do you use?