On Apr 11, 10:01 am, "Pereira de Lisboa"
wrote:
Hi,
a few books in my personal library have some strange reddish stains
along the upper border. I've just posted on Flickr some photos about
this issue: seehttp://www.flickr.com/photos/7780863@N06/The books
are 5-6 years old. What could be the cause? Mould, moisture, bad
quality paper? Must I isolate the stained books? Are they contagious
for other books?
Thanks
Pereira

Sounds like foxing:
http://en.wikipedia.org/wiki/Foxing