Printing several booklets of single book for future sewing

[EEvgeniy]

First of all, I apologies if that question was discussed before, but I don't know specific English vocabulary for that, so can't find a solution.

But.

When I was making a family photobook last time, I was offered to craft it as a "real book" — with hard cover and binding using sewing machine.

That's was interesting, because when crafting (making?) a book, inner block is divided into a booklets with a multiple of four pages. Each of these booklets has it's own sequence number to facilitate the subsequent assembly of the binding (and apparently this number will be hidden in the binding).

In the printing options of the Publisher there's and option — Booklet — that do that, but for the whole volumes of pages. Maybe there's also an option somewhat like to "start new booklet every XX pages"?

Thanks!

[thomaso]

36 minutes ago, EEvgeniy said:

I don't know specific English vocabulary

A forum search for "print book signature" might help.

Book Fold: Setting your pages to “book fold” allows your pages to be put in proper order for folding; this is called imposition. This is why your pages will appear out of order before folding. Each sheet of paper. has four book pages (two front and two back).

Signature: A signature is a group of pages you have folded to form a small portion of your book. The size of your book will determine how many signatures you will have. Typically, a signature will consist of 8-16 sheets of paper, depending on your preference. 

Text Block:The pages of your book that have been folded and sewn together.

32 minutes ago, EEvgeniy said:

inner block is divided into a booklets with a multiple of four pages

You probably want to bind 4 sheets (four physical papers with 4 pages each) = 16 pages per signature.

Unfortunately, printing in signatures is not a feature of Affinity. As workaround you could try type the page numbers in the required order as mentioned by @walt.farrell in this thread:

[Oufti]

15 hours ago, thomaso said:

As workaround you could try type the page numbers in the required order

Yes, doing so and printing recto-verso (i.e. on both sides) with 2-up pages across and with short side page flipping will give the desired result.

Difficulty is to establish this page numbers order. You can do that with the method of "a snake going down the tree and climbing up again". 
At the top, you write the last and first page numbers of the signature, then you make zigzags, like that:

— BTW @walt.farrell was totally right saying that for subsequent signatures you've only to add 16 to each page number of the first sequence of pages (16-1, 2-15, …, 8-9) → (32-17, 18-31, …, 24-25) etc. 

This calculation is not really difficult but tedious. Fortunately, that's what spreadsheets are made for!  
You can find here one made with Excel by @Robert Leblanc or, if you own a Mac, you could use this one I made with Numbers, downloadable in the Resources section: