Five Simple Steps to Designing Grid Systems: Grid Systems for Web Design, Part 1
http://www.markboulton.co.uk/journal/comments/five_simple_steps_to_designing_grid_systems_part_3/

Boulton, Mark
Mark Boulton
2007

Abstract:

Designing grid systems for print is considerably more straight forward than designing grid systems for the web. First off,in print, the designer has a fixed media size - the paper size (or packaging, poster, whatever). Let's say a print designer has designed a magazine. The reader of this magazine can't suddenly increase the font size if they find it difficult to read - well they just move it closer to their eyes I guess. This is just one consideration, there are more but I'm sure you get the point.