The professional way is this:
Bind all your e.g. 40 pages to a book (I did it) .
This means: Include pages A4 portrait 1, 2, ... 40 in right order in the book content,
which is assigned to the first page. This is good also for PDF-conversion.
Then use plug-in "assembly" (German: Montage)
Here define a page A3 landscape and an assembling mode.
The unpleasant feature is, that you have to deal also with
simplex or duplex printing.
Therefore new start:
Assumed you want to assemble page 40 + 1 ,each A4 portrait, on one A3 landscape.
Then 39 + 2, 38 + 3 and so on for two passes of simplex printing with manual reversing.
First you would like to print all pages 40+1, 38+3 and so on simplex.
Then you must copy all pages into a new folder and define the book completely new:
40, 1; 38, 3; ... Last page of cover is left !
2, 39; 4, 37; ... Page 2 is left !
Then use mode: "2 pages on one" and print first pass (10 sheets of paper A3 landscape)
Then turn printed paper and print second pass (rear side, starting with 2 );
High risc, that you print on the wrong page! Good luck.
G.Hoffmann (Germany)
Then [sig][/sig]