Stamp collectors: What do you keep BIG stamp sheets in?

I have the German (Lighthouse?) acid-free plastic pages, and they hold 90% of my stamps.

But the really large stamp sheets (like the new 50-stamp Greetings from America) won’t find in those. Are there archive-safe over-sized stamp protectors?

Dunno offhand, but a good starting point would be Google, “oversized stamp protectors”.

One hit.