Reply To: Need to activate "include slug area" on a print booklet function

I don’t think you can turn on that checkbox. That is odd. I wonder why they do not allow that.
You can do it, though. It involves setting the Bleed values manually — for example, if you have a slug at the top, you need to set the Top AND Bottom bleed value to a larger amount, which you can only do if you change the Margins settings in the Print Booklet dialog box.
I will write up a blog post about this, because it is so weird and non-intuitive!