When did plastic audiophile sleeves come out?

As the title says, when were plastic sleeves, like the ones mofi make put on the market?

Just out of curiosity, thx.

 

They might have been out earlier but I have some from the mid to late '70's when I started buying records.

I'd guess they were around even earlier than that.

 

Discwasher sold them exclusively as VRP or Valuable Record Protectors. Rice Paper sleeves were, to my knowledge always included with MFSL releases. The were included by JVC who pressed their record originally. When MoFi brought manufacturing to RTI, they imported the sleeves for their records. When Discwasher went out of business, MoFi started selling them with their branding. But MoFi does not have an exclusive licence the way Discwasher did.

 

The above matches my recollection.

 

Am embarrassed to say that l can remember them in the mid 1970's.

 

Early 70s. I much prefer plastic lined paper alternatives however and that goes even further back.