Hello Mediawiki people,
I noticed that the line length is very long on PDF ebooks generated out of Wikipedia articles. It slows down reading. The Wikipedia people suggested that I report the issue on this list.
Research has shown that the perfect line length for printed texts is about 66 characters, including spaces. Anything from 45 to 75 is good.
Here's the first search result on the subject I googled up, citing perhaps the most respected authority in typography, Robert Bringhurst: http://www.typophile.com/node/78173
For some mysterious reasons the ideal line length for computer screens seems to be longer -- I have no recommendations for that. But if you're aiming the Wikipedia PDFs for printing, the line length should surely be shorter!
Mikko Lehtinen