flavio81 wrote:My opinion is exactly the same as ld's. Also:Quite a few had a surface that looked dull and when played had a consitent background hiss.
Can't see why this should be blamed to the inner sleeve materials when this perfectly fits the description of a record worn by too many playbacks with a cheap record player at very high (>8gm) pressures, probably with a worn sapphire, or a jukebox on similar condition. Given that it's a 45RPM single, the latter is probable. (A sapphire stylus is rated for 50h of stylus life - how many bar owners actually changed the sapphire stylus on their jukeboxes every week?!) Even more likely if the record itself is made not from vinyl but from polystyrene.
The razor knocks your analysis down the list a bit, flavio81, because of all the assumptions you've just made in the above. There's something definitely going on here and it's not wear. I just now pulled out a Bjork double-45 that's not that old and not played much and the dull surface is there (much to my horror) along with the noise and, yes, it was in a PVC cover although now it is not! Incidentally I think it's the outer not inner sleeve that is the suspected culprit. I have dozens of my older records that were transported to here (Bangkok) from Melbourne that exhibit the exact symptoms described - a dulling of the surface and noisy playback. Most of them haven't been played since transportation and they were never that way in Australia. The vast majority of that older collection have the PVC outer covers that were very typical of Aussie record packaging. One record had the cover artwork "shadowed" into the dullness (believe it or not) which made me think that some kind of radiation was involved - it was in a group of records stored underneath an LCD TV. But it's the only example that has that exact manifestation so the radiation theory might be a red herring but I'd love to know what others think about that. That aforementioned Bjork disc is the first and only, as I'm aware, of my recent (2007 & later) record purchases to be afflicted by this syndrome and it's one of very few of those purchases to be in a protective cover of the type in question so let's just state that there is a notable coincidence here.
It seems likely to me that climate is a factor, but not the sole cause.