Odd page sizes.. why don't d20 products use 8.5x11?

[uv23]

Really curious about this one. They seem to be 8.5x10.5 or something close but they are definitely smaller than standard page size. Is there a particular reason for this or is it just an old RPG standard that has been perpetuated?

 

[Mystic Eye]

There is a real simple reason for that. The standard printing press these days runs at 8.5 X 10.7/8 and this is what is normally used to produce an 8.5 X 11 sized book.
If you run at a full 8.5 X 11 you are on a "big" press and this actually costs more. It is only pennies per book but it adds up when you print thousands.

So, that is why.

 

[uv23]

Thanks for the info does it cause problems when formatting your product in a dtp app? I don't recall seeing that size in InDesign.