My experience with some old paper

I just got back into shooting film again and have a bunch of 20 year out of date film and paper. The film was kept in my fridge and it all seems fine. The paper on the other hand... I had a bunch kodak polymax II RC, all of it is junk. Take a sheet out of the bag and toss it in developer and it's at least 20% gray. The forte paper is the same. I tested at least 15 different boxes of it, some of it was unopened, and none of it was even remotely usable.

What's interesting is so far all the Ilford paper seems OK. The contrast seems maybe a little low but there is no fogging at all. Still have to test the rest of the Ilford paper but it least some of it survived. Weird it was all stored together at room temp in the same place and the kodak/forte paper is garbage, but the Ilford seems OK and all was RC multigrade. I do have some FB Ilford, I hope it survived!

FB generally ages better and RC is usually a hit or miss affair (emphasis on miss). Nice that the Ilford did well in your case. The Ilford FB may be fine and dandy as well; give it a try, you may be lucky. Long story short: it's sort of unpredictable, but you get lucky sometimes. I was given some really old (pre 1980) Agfa FB papers and they seem as good as new...

Yeah, the bummer is the vast majority of it was kodak paper lol. I found years ago I liked the look of polymax II over the ilford back then, seemed "crisper"? This old ilford paper needed a lot of magenta cranked in the get even a normal contrast and the blacks aren't super deep. I think I'm just gonna toss all the RC paper instead of fighting with it. I did get some new ultrafine elite VC RC pearl in 5X7 from a local store a couple of weeks ago and like the way it looks, so might try the 8X10 size of it.

The paper that didn't survive age well can possibly be used for lith printing (search on here if you aren't familiar with it, Freestyle sells Moersch Easy Lith, too) and can definitely be used for lumen printing. It's too bad more of yours didn't age well, but 20 years is a bit much for paper in my experience.

The substrate can be used by carbon printers .
And the Ilford might serve your needs for contact proof sheets.

I was given boxes and boxes of Kodak RC paper that are at least 20-years old by a photographer who went digital I’m hoping I can use it for paper negatives without having to preflash. We’ll see.

I've been using 20+ year old RC paper for years, just used some yesterday ! I don't have it stored in a humid environment though and the temp where it is stored doesn't really fluxuate and stays between 65ish and 75ish... fiber paper too. The suggestions for using your paper for paper negatives, lumen prints and liths is fantastic! Sounds like you have a great stash !