Ciba RC was available almost until the end. I never had any issues with it, of any kind. It was hypothetically available even in big rolls, so someone somewhere must have used it that way. But it was nowhere near as popular as the deluxe glossy product. But either one had to be
used rather promptly after thaw or would develop crossover (typically beyond correction within 6 mo). I never particularly like the sorta stippled mat surface of the Pearl product. Probably the most beautiful color paper surface I have even seen was a bad batch of the polyester material where the gelatin weirdly dried to a luscious lustre less than its intended full gloss. They didn't either know how it happened or how to replicate it, but blamed it on bad gelatin. I was refunded - but that was not the point - I wanted more of it! I still have those prints, and they still look just as new as all the others. The demise of Ciba is eventually UV. They seem extremely stable in dark storage, unless mildew
get involved, which they as also susceptible to. But I never took a liking to RC black and white papers for personal use, just for quickie commercial projects intended for publishing or maybe bound portfolios for an architectural firms etc. I'm pretty much a fiber-base and drymount junkie.