I'm thinking of never bagging the cels again and switching over from celbags to either naked in the portfolios (with archival tissue paper) in between the black inserts and moving some to museum grade storage boxes with acid free interleaving paper and archival folders. I'm just really thinking over the years that cel bags just didn't seem to cut it and i always ventilated them and never closed them, with the exception of a few of my cels in cel bags that are also in top loaders. Also over the years I've been reading up on preservation and for those cels that may have already started degradation, that any plastics will react and accelerate it's degradation. Most degradation may not be obvious especially if you don't have AD strips (which I can't find anywhere), not obvious until you smell it.
A long time ago when i first started collecting, there was this "collection" i stumbled upon of Kenshin OVA cels that was highly prized. The person who collected was involved in bringing the Tsuioku-hen OVA to the US and as a gift, he received a large collection of cels. When he sold a couple of those cels to me, there was a photo of the way the collection was stored - they were filed the same way, archival tissue paper in acid free file folders inside a museum grade box - not a single plastic to be found in those photos and when I received the few cels I could afford, they were not in bags but came in individual file folders w/ tissue paper. I didn't quite get it - I thought it was all rather cheap way to store until years later I find that museum grade boxes were pretty expensive so those folders and tissue paper must've been archival. This was maybe 15 years ago. I didn't really think about preserving anything. I was just wanting to collect everything.

Sorry this seems long winded. Anybody else thinking over their experience that for cels it's just not advisable to be in poly bags even if you do air it out, kept it ventilated etc. etc.?