The Pioneer 12" x 12" top loading page protectors may be the most versatile page protectors you'll ever find. They are made as refills for Pioneer Memory Albums, but they will also work in most post bound, three-ring or strap-hinge albums. Made of acid-free, lignin-free and PVC-free materials, they are extremely durable. You don't have to worry that your album will come apart as you're flipping through your pages. This pack of 5 refill page protectors (10 sides) are made of seamless, clear polypropylene. They come with heavy white paper scrapbook inserts and two post extensions. These page protectors are designed for Pioneer Memory Album MB-10, FTM-12, BF-12, TM-12, and WF-12 and most post bound or three-ring memory books.
These page protectors do not hold 12x12 scrapbook pages, especially if you put any dimensional embellishments on your pages. I had to cut 1/4 inch off each of my pages just to get them to slip in the protectors and my pages still curled and buckled.
These are very sturdy stock paper. They went into my album and fit very well. I don't have any of my papers or stuff sticking out like other reviewers said, everything fit wonderfully. I absolutely love my album, it's going to be a memory book for my Daddy. It holds all of the pictures and a LOT of his newspaper articles. My sister loved it so much she had me order one for her as well. I needed 3 extra packs of these refill pages to complete it.