Here’s 2 examples infront of me right now. On a couple of 7"s i’d love to have priced up at the shop but cannot sell haha. It’s def something that doesn’t effect everyone or every record collection - but it’s all to do with the PVC burn.
Discogs Groups - vinyl burn??? - a discussion here too.
My dad got sucked into buying a quadraphonic sound system in the 70’s. The stereo and the speakers took up a good proportion of the lounge of the flat we lived in in Moonee Ponds. The expectation was that bands were going to start producing quadraphonic albums. Never happened. I think I remember one Doobie Brothers album (stampede?) that was quadraphonic. Other than that there was a test album of some Dixie Jazz band that he listened to on occasion.
Pretty sure Pink Floyd Dark Side Of The Moon was quite famously available in quadraphonic pressings.
Very interesting @crumbs. You’re the record shop guy, so I trust what you’re saying…
So it seems that polypropylene (rather than PVC) sleeves are the recommendation.
A quick scan of Dr Google tells me they come in a variety of film thicknesses (anywhere from 50 - 100 micron, without looking too hard). Any idea which thickness is better (from a vinyl perspective, rather than a matter of durability)?
Bag rash is such a strange phenomenon. With no cure.
Ive only had a handfull of records fall victim to it. Strangest thing is, once it sets in, it seems to get worse after you try cleaning the record.
I’ve got a handful of 12" singles which have been in a thick plastic outer sleeve for the better part of 40 years… I’m now off to investigate… 
Don’t stress on it too much - like i said it’s not always the case. But those types of sleeves are the only common denominator from my experience. And i’m not an expert any shape or form but have spent hours trying to clean ghosted records that are worth a mint! We use these at the shop for our 2nd hand stock:
Have already found a couple of examples…
Quite noticeable in mid-80’s 7" and 12" singles which had only the picture sleeve, and didn’t come with those thin, semi-opaque plastic inner sleeves…
Just as maddening though, a couple of lightly-coloured (or predominantly white) sleeves which have yellowed a bit in parts from the bag yellowing with age…
FFS…
The outer protective sleeves are important but it’s all to do with the material. I can buy bags of some here in Japan that feel smoother and non-stick, not too thick and have be had really great long lasting ones in Australia too.
Edit: sorry, should’ve read further, already been discussed
So it turns out these fkn things - which plenty of my treasured vinyls have been proudly wrapped in - are very bad…
There’s these inner sleeves that are bad news too. Theyll ghost up your records within 12 months. Theyre kind of a clear pinkinsh colour and are strange to the touch. Almost like that weird plumbers tape.
I bought Hendrix at Winterland 8lp box set that came with them…its still hard for me to talk about…
I had a record by Les Savy Fav that, as a gimmick, they sold in a shower cap bag. With the shower caps in there up against the vinyl. 
The rarity meant the record could fetch $80-100 but the two copies I came across cheap in stores here were completely unplayable and couldn’t be saved. Just totally hazed over. I didn’t wanna rip anyone off so I sold them cheap online fully letting the buyer know that they were probably buying junk.
Makes me glad I’m not about the resale.
Send me your ghosties!
What a fkn pịss-off… finding out that what you did to protect your records has actually hurt them… 
Anyways, here’s another couple of the culprits… remnants from shops long gone the way of the dodo…
I went down the bag rash rabbit hole about 8 or 9 years ago. Ended up ditching all outer sleeve covers, and started a cleaning/re- inner sleeving record system i still use today.
My records covers have sat naked and bare ever since. I just lost all trust for outer sleeve covers and i havent looked back. No more bag rash, although i do get ‘ring wear’ on the covers. But I can live with that…sorta makes em look cooler.
So, being a chemist by trade, if I had to guess…
PVC, being an oil-based plastic, slowly gives off fumes as it ages, which reacts with the vinyl (also an oil-based plastic). If there’s something else present in the packaging which is more reactive that will be the sacrificial reactant and protect the vinyl. If not, the vinyl bears the brunt of it.
Well, fark…
Had a look at a collection of 100 LPs which included Zeppelin, Hendrix, Pink Floyd, Clapton both Richard & Eric, Fleetwood Mac etc etc. Told the gentleman the problem and got asked to leave. Rang me a week later and sold them to me for $5 for the covers - completely covered (one side only) with what we call vinyl rot!
Yikes.
