I finally got my first Educational Note! It's a "starter" but I like it. I couldn't find any pinholes, tears, or terribly distracting creases, and I think I got it for a fair price. The problem is that it has a stain (and a rather unfortunately placed one, I might add -- at least on the front!) A trusted friend explained that it's a rust stain, perhaps from a paperclip years ago. Do these types of stains ever spread or eat away at the paper? I'm unsure if it appears on both sides because the paperclip touched both sides, or because the rust has gone through the paper.
I have never heard of them spreading but it is a rust stain and i would agree that it was probably from a paperclip. I would keep it in a mylar holder.
Fe2O3 only destroy metals that contain iron. However as you notice it's a very effective stain for fabrics.
