I use these sheet protectors in a three-ring notebook to store and display Commemorative Pages in my stamp collection. They hold two pages back-to-back and are clear and easy to view through. They are strong but thinner than the old vinyl sheet protectors and don't interact with the glue the way the vinyl plasticizers did.
I went with the staples brand of these after using Avery just because it was a lot cheaper. They are just as strong and everything but are strangely harder to load with paper. For some reason it wants to stick going in rather than sliding smoothly. A small inconvenience for the price savings but there you go.