Interesting feedback. I was first schooled on the problem while a student at the University of Washington. I bought all my records at Standard Record & HiFi, whose owner, Mrs. Smith, was quite firm in advising all clients to do a few things with our new precious records: 1. Take the cellophane cover off the jacket 2. Clean the record (in those days we used a Parastat, or later a new fangled thing Discwasher) and 3. Throw away the paper sleeve and use a poly sleeve. Mold was a potential problem and the reason for ditching the cellophane covers. I worked at a HiFi store all through college and saw a lot more records than otherwise might have been the case. Through personal observation mold on vinyl was a thing and it seemed always to be associated with records being kept in plastic wrapped jackets. After graduation I moved to San Diego, another stint in the HiFi business, more records, more similar observations. That all ended in 1978. Last month I got involved with a large ~8,000 collection. The records are mostly jacketed in plastic, inner sleeves are mostly paper, they are under AC and at a guess about 60%, plus or minus,have mold on the vinyl. It takes two full cycles on the VPI to get it off. And of course it is still on the labels and on the jacket. It is a PITA. If you don't have this problem don't let this concern you, it is a heads up to keep people from having to deal with anything like this.
