[TanksAndSpartans]

For raw cards, I don't like toploaders because they are made with PVC (I've seen old ones yellow which shows they aren't made with materials archivists would use imo). I look for archival safe plastics. Mylar/polyester is the gold standard, but I don't like working with it. I prefer polypropylene (I check my penny sleeves and binder sheets are made of this before purchasing, typically they are).

Humidity is a different issue. I would recommend a temperature controlled space - no basements or attics. Keeping the humidity within a certain range probably isn't feasible, but my theory is if you're comfortable, the cards are probably fine.