A6 sized book - print doublesided on A4 with fewer signatures

Question

Ref: Two-sided printing of A6 pages on A4 paper

Enough discussion is done on the question that is shared in the above mentioned link.

My new question: The above mentioned link gives 8 A6 pages on 2 A4 pages [8 on 2 book, @AndrewStacey 's answer accepted]. For an A6 book that is 240 pages long, we end up with 30 signatures of A6 size each containing 8 pages. Each signature has just 2 double sided sheets [A6 size]. So to make a complete book, one needs to staple each of the 30 signatures and bind them together.

Can it be possible to have fewer signatures by having, for example, 16 A6 pages laid out over 4 A4 pages [16 on 4book]? Or better still, 24 A6 pages over 6 A4 pages [24 on 6 book]? That would make the stapling and binding process easier.

I am not sure if I'm asking too much but I want to reduce the labour involved in the binding process since a A6 sized book already presents many space induced challenges than an A5/A4 sized book.

Answer 1

It would be nice if there were a better way to create the layout than just cut-and-paste, but once it's defined then the length of the definition can easily be hidden in a style file. pgfmorepages is built on pgfpages which uses xkeyval for its key handling and as far as I can tell, xkeyval doesn't allow for grouping keys into a single style in the manner of pgfkeys which would make this easier.

Anyway, this is - I think - the 24 on 6 layout you're after. I've defined a meta page style which figures out which physical page a logical page should end up on, where it should be, and what rotation. This reads in the number of physical and logical pages in the signature so to change it to 8 on 4 then you just change the lines that set the physical and logical pages of the layout (I'd also change the name, of course).

\documentclass{article}
%\url{https://tex.stackexchange.com/q/660686/86}
%Adapted from \url{https://tex.stackexchange.com/q/638802/86}
%Adapted from \url{http://tex.stackexchange.com/q/279042/86}
\usepackage{pgfmorepages}
\makeatletter
\newcommand\setsignaturepage[1]{%
% Figure out which page it is on
  \pgfmathtruncatemacro\signaturepage{%
    2((\pgf@physicalpages-1)/2 - abs(floor( (#1-1)/4) - (\pgf@physicalpages-1)/2))
    +
    1.5 - abs(mod(#1-1,4) - 1.5)
    +
    1
  }%
% Figure out the rotation angle
  \pgfmathtruncatemacro\signatureangle{%
    90(mod(#1+1,4) - mod(#1+1,2))
  }%
% Figure out which side of the page it's on
  \pgfmathsetmacro\signaturex{%
    #1 > (\pgf@logicalpages/2) ? .25 : .75
  }%
% Figure out whether it is at the top or bottom of the page
  \pgfmathsetmacro\signaturey{%
    .25 + .25*(mod(#1+1,4) - mod(#1+1,2))
  }%
% Put all that together into a single page definition
  \edef\signatureonpage{%
    \noexpand\pgfpagesphysicalpage{\signaturepage}{}%
    \noexpand\pgfpageslogicalpageoptions{#1}{%
      rotation=\signatureangle,%
      center=\noexpand\pgfpoint{\signaturex\noexpand\pgfphysicalwidth}{\signaturey\noexpand\pgfphysicalheight}%
    }%
  }%
  \signatureonpage
}
\pgfpagesdeclarelayout{24 on 6, book format}
{%
  \edef\pgfpageoptionheight{\the\paperheight}
  \edef\pgfpageoptionwidth{\the\paperwidth}
  \def\pgfpageoptionborder{0pt}
  \def\pgfpageoptionfirstshipout{1}
}%
{%
  \pgfpagesphysicalpageoptions
  {%
    logical pages=24,%
    physical pages=6,%
    physical height=\pgfpageoptionheight,%
    physical width=\pgfpageoptionwidth,%
    current logical shipout=\pgfpageoptionfirstshipout%
  }
  \pgfpagessetdefaults{%
    border shrink=\noexpand\pgfpageoptionborder,%
    resized width=.5\noexpand\pgfphysicalwidth,%
    resized height=.5\noexpand\pgfphysicalheight,%
  }
  \newcount\pgf@mp@pg
  \pgf@mp@pg=0
  \loop
  \advance\pgf@mp@pg by 1
  \setsignaturepage{\the\pgf@mp@pg}
  \ifnum\pgf@mp@pg < \pgf@logicalpages \repeat
}
\makeatother
\pgfpagesuselayout{24 on 6, book format}
\newcommand\dopage{%
\noindent\resizebox{.99\linewidth}{!}{Page \thepage}
  \newpage}
\begin{document}
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\dopage\dopage
\end{document}