I've asked Staples if these sheet protectors are acid free because for one archival use I need them to last at least a century. So far Staples haven't answered.
Mine came wavy it does dissapear after a while but check yours out if you need them for a presentation. It does do its job and I find them as good as the leading brand.
lNeed a sturdy binder for large volume of sheets. The combined weight will pull the rings apart and slip through the crack if your careless. Then you have to reinsert the sheet in the rings.