polyethylene vs polyester for film sleeves?

[Darren Kruger]

I'm looking to buy some fold locks for my 8x10 film and I see that there are film sleeves made of polyethylene and polyester. In the past I have purchased polyester sleeves for my 4x5 film.

What are the advantages and disadvantages of polyethylene and polyester?

-Darren

[Robert Hughes]

Polyethylene is softer, so will be less likely to scratch a negative. OTOH, it will scratch more easily itself, so if you contact print through the sleeve, you'll still see the scratch. It just won't be on your negative, which is good.

[Oren Grad]

I haven't seen fold lock sleeves in polyethylene - only slide-in pages and "negative preservers" such as those made by PrintFile and VueAll. The polyethylene in these products is very soft - I'm not even sure it's stiff enough to make a decent fold lock sleeve.

I do use fold lock sleeves in polypropylene, which tends to be much cheaper than polyester. Polyester is sometimes marginally clearer, but I don't contact print through the sleeves so it doesn't matter. Although either is stiffer than polyethylene, I think the risk of scratching is actually lower because you don't have to slide the negative in against pressure - just open the sleeve and drop the negative in.