Confusion regarding bleed/slug etc.

Question

Hi there,
I'm currently attempting to set up a document which will be printed and professionally bound.
Scans of my images will be placed in the document along with text, shapes ect.
The binders informed me that for the A5 document (A4 pages halfed lengthways when bound) I need to set a "3-5mm bleed all around" and "25mm from gutter".
Does that mean i set the gutter at 25mm and bleed at 5mm?
Do i need to check what they need for margins and slug? They never mentioned those..
And finally, I need to set a fold line directly down the middle of the A4 page - how would I go about doing that?
Any response is greatly appreciated!
Thanks

Answer 1

OK, so  I THINK I understand what yo are doing. Pages "1" and "2" will be printed in the same side of one sheet, the other side will be blank. 3 & 4 will go on the next sheet, and so forth. The sheets will get printed, die cut, and folded, then assembled into a book block for binding (almost certainly glued, not stitched) using the loose edges in the binding.
If that's correct, then I might set up as A4 non-facing pages since the back of all sheets will be blank and normal imposition is not possible, and on each page I would make two columns to represent the two pages that will be on that "leaf" in the book. Set the bleed top and bottom at the 3-5 mm, and left and right at the larger dimension as hese are the edges that will wind up being in the grind-off area for binding (what I presume the printer is calling the gutter). For the gutter between columns, use twice the value of what would be the outside margin on a regular book  because when folded iin half that gutter becomes the outside page margin. Set the top and bottom margins to whatever you like, and left and right will be what would normally be the margin at the spine area, so I would make them a little larger. You can add a vrtical guide at the centerline for reference on the master page. Objects that bleed to the outside of the finished book should extend exactly to that line, not beyond.
The tricky part is if there will be objects that need to cross over adjacent spreads of the finished book. For those cases you could try setting the pages not to shuffle and drag two pages together in the Pages panel so you are looking at what is essentially a four-page spread.
A different approach would be to set up as A5 facing pages, do the entire layout as if this were a "normal" book, then place those pages side-by-side into a new A4 document. This would allow you to use automatic page numbering, if you want it, and would make crossovers much easier.