Japanese imports were the first records that used polypropylene record sleeves. People actual referred to them as Japanese Mylar sleeves although the material was actually polypropylene. They put this tag on them because the material was so crystal clear the only thing that matched it in clarity was Mylar D.
Mylar D was the name that DuPont used to brand their polyester material. People were unfamiliar with polypropylene in the US at the time (late 80’s, early 90’s). The clarity of the material as well as the reseal flap made everyone want to display their records in these Japanese Mylar sleeves. We searched for years to find a vendor that could match the clarity of the material and the proper release and tack on the reseal tape. At the time there was also an issue with the material itself.
When it was first manufactured, it appeared to be as clear as glass, but over the months, it would start to pucker and what people loved about it (the clarity) began to degrade and the material became distorted. Yet another obstacle to overcome. The problem was in the manufacturing of the material. In order prevent the “pucker”, the material needed to be stretched both in the length and width at the time of manufacturing. We eventually found a company that understood the process.
Another issue was the seals on the polypropylene sleeves. Most manufacturers could only supply sleeves with weak side seals that easily ripped when the record was put in the sleeve. The search continued and eventually we found a company that was able to provide the clarity, the proper tape, good side seams and the proper “stretch” of the material to prevent the pucker.
The last hurdle was to have the material tested by an independent lab for its safe storage properties. It passed the Photo Activity test for safe acid-free storage with flying colors – and the rest is history. After three to four years of research we were finally able to start our extremely popular line of polypropylene record sleeves.
To see our full line of Poly Sleeves check out one or all of the links below:
The Bags Unlimited Blog 