Reddit mentions of 50 BCW 12" Paper & Plastic Polylined Record Inner Sleeves for LP Vinyl Record Albums

I've been into record collecting for a few years now. I would definitely not use the sleeves with artwork, and I would strongly recommend not using the paper sleeves either, but rather picking up some poly-lined sleeves. I use these things not just for my NIN records, but for All of my records. I throw away any generic white sleeves, house the record in one of these poly-lined sleeves, and keep that and the empty sleeve with the artwork inside the jacket.

If you're using the sleeves with the artwork, they are likely to be damaged over time. The seems will probably split, particularly at side opposite the opening. Not only does this damage part of that packaging which contains artwork, but it creates dust and pulp as the paper breaks down from use, which can then get into your record causing popping, crackling and scratches.

The paper sleeves that come with the records do a pretty good job, and the eventual wear won't damage anything with artwork. However, the pulp/dust problem can still crop up. Also, regular paper sleeves can be kind of abrasive. They're not something that's going to create a big scratch, but they can contribute to wear on the record.

The poly-lined sleeves have a later of slick plastic that adds durability and smoothness. The plastic isn't abrasive and doesn't wear down the same way. It protects the record better, while keeping the record from damaging the jacket or any other artwork.

https://www.amazon.com/gp/product/B019R8HBMK/ref=od_aui_detailpages00?ie=UTF8&psc=1

these are nice.

1. I don’t know, sorry. All I do know is that vinyl collectors are picky! So don’t over-estimate condition
   
   
2. Use these (or something similar) for the records, and get something like this to Mail them
   
   Hope that helps!
   
   EDIT: I just realized you were talking about 45s and not 33s. My advice still stands, just use stuff for 45s instead of 33s like I picked out.