Hello Eeveryone,

This is my first post and I apologize in advance if I make some mistakes.

I'm trying to print a 40 pages booklet A4 that in the pagination has no margin.
Obviously in this PDF all the pages are in A4 but I choose to print in A3 to achieve a folding booklet by choosing the booklet option in the printing section.

The problem that that I don't know how to solve is that in the middle between two pages there is a margin, like a gap, and I don't understand why this happens sine it's the middle of an A3 pages and It's a printable area.
Of course I understand the top, bottom, left and right margin but I cant figure out why this there is a margin in the middle of the page. (see the blue circle in the photo)

Thank you very much for your patience.

Have a nice day!!