I've just purchased a 3800, and am in the process of making prints that'll function as portfolio pages with no mylar or plastic cover of any kind. I haven't made a final decision between a fiber matte (kind of fine-artsy, beautiful) and something glossier, like a luster (more "photographic", less pleasing to the touch). In any event these pages will be handled a lot.
Is there an industry-standard spray (hopefully something invisible, and maybe even archival) that will help protect these prints from fingerprints and scratches out in the real world?
I just recently experimented with a variety of papers looking for one that would be best at hiding fingerprint smudges and would hold up to handling without sleeves. I did not try any sprays. The short answer is that Hahnemuhle FineArt Baryta seemed to do the best. It has a nice weight and "feel" to it, too.
Epson Luster was a runner-up, but I didn't care for the epson brand emblazoned on the back side. I also tried Harmon Professional Gloss FB Al, Ilford Galerie Smooth Pearl, Ilford Gold Fibre Silk, Epson Exhibition (didn't have the brand name on the back...), but not seemed to hold up to my un-scientific fingerprint testing as well as the Hahn FAB. You can get a bunch of these in a sample pack from Atlex and try it yourself!
I didn't experiment with matte papers for smudge/handling, but if you want matte, you might try Epson Velvet Fine Art. I have a VFA test print here and it seems to be holding up well to my handling and doesn't show fingerprints.
Let us know what you finally decide! I would be particularly interested if you determined that the sprays helped much.