# Why is a blank page inserted in the middle of the first signature when impositioning with Context?

Tonight I'm impositioning a book for doublesided printing on A4 sheets. The book is in A5 format and will be bound with octavo signatures (4 pieces of A4 sheet are folded in half to form 16 pages of the book.

The book compile well both without and with imposition setting (see below), but when impositioning the book I get a mystery blank sheet at the middle spread of the first signature. This blank page does not occur if I remove the impositioning: \setuparranging[2*2*4,rotated].

This is what the middle spread of the first signature look like:

:-----:-----:
¦page ¦     ¦
¦10   ¦blank¦
¦     ¦     ¦
¦_____¦_____¦


Meaning that the same sheet (the middle one of the first signature) will look like this if the sheet is turned over by itself so we can see the backside of it (top up).

:-----:-----:
¦     ¦ page¦
¦blank¦    9¦
¦     ¦     ¦
¦_____¦_____¦


The settings I use is as follows:

\enableregime   [utf-8]
\mainlanguage   [sv]

%% Typografi %%
\setupbodyfontenvironment [default][em=italic] % Använd kursiv för em
\setupbodyfont [cmr,10pt] % 10.6 för att fylla 64 sidor

\setupindenting[9mm]

% Indentera kommande rader i stycken
\definestartstop
[exdent]
[before={\startnarrower[left]\setupindenting[-\leftskip,yes]},
after=\stopnarrower]

\setupblank[fixed,line]

\setupfootnotes[way=bypage, conversion=set 2,style={\setupbodyfont[7pt]},bodyfont={\setupbodyfont[7pt]}] % Använd symboler istället för siffor för fotnoterna

% intro = behåll överstående stycke med listan, ej sidbrytning.
% autointro = ingen sidbrytn om stycket innan har bara max 2 rader
\setupitemize[packed,inmargin,joinedup,autointro]
\definesymbol[p][→] % definiera symboler för listor. Asterisk, ej upphöjd = ∗

% Stil för text i marginalen. Setupbodyfont ska användas, och inte small. Small gör bara texten mindre, inte radavståndet, det ser alltså inte bra ut.
% Används så här: \inmargin{Text som ska vara i marginalen}

\setupinmargin[style={\setupbodyfont[7pt]}]

% Citationstecken

%\setuplanguage[sv][leftquote=\leftguillemot,rightquote=\rightguillemot,
%leftquotation=\leftguillemot,rightquotation=\leftguillemot]

%\setupdelimitedtext[quotation:1][left=»,right=«]
%\setupdelimitedtext[quotation:2][left=›,right=‹]

\setupdelimitedtext[quotation:1][left=»,right=»]
\setupdelimitedtext[quotation:2][left=',right=']

%% Layout %%
\setuppapersize[A5][A4] % ,landscape
\setuplayout [location=middle,
height=189mm, % höjd på text+sidfot+sidhuvud -- Dessa tre första är de enda som påverkar brödtextsfältets storlek
width=95mm, % bredd på text
topspace=22mm, % utrymme över sidhuvud
backspace=17mm, % utrymme mellan text och rygg
headerdistance=10pt, % mellan sidhuvud och text
footerdistance=4mm, % text till sidfot
bottomspace=4mm, % mellan sidfot och sidslut
footer=37mm,
leftmargindistance=2mm, % text till vänstermarginal
leftmargin=13mm,
leftedge=2mm, % vänstermarg rygg
rightmargindistance=2mm,
rightmargin=33mm,
rightedge=2mm,
grid=yes,
marking=on,]

% Dubbelsidig utskrift av 4-arkssignaturer
\setuparranging[2*2*4,rotated]

%% Figurer %%
\useexternalfigure [logo][faw_logo][width=50mm]
\setupexternalfigures[directory={./img}]

\definelayer[fullpage]  % name of the layer
[x=0mm, y=0mm,  % from upper left corner of paper
width=\paperwidth, height=\paperheight] % let the layer cover the full paper

%% BÖRJA BOK %%

\starttext

\clubpenalty=10000
\widowpenalty=10000


What could cause this behaviour? What could I look into to solve it?

Looking forward to your thoughts! Please comment if there's some info I left out and I'll provide it.

-
Workaround: Imposition in other software, like psbook. –  PetaspeedBeaver Mar 6 '13 at 9:24

This question would be easier to answer if you could provide a minimal example that still displays the problem.

I suspect that your problem has to do with the number of pages in your document. \setuparranging[2*2*4] arranges groups of 16 pages into a signature. If the number of pages in your document is not a multiple of 16, then the arranger will add blank pages where the 'missing' pages are.

Below is a description of how \setuparranging[2*2*4] arranges 12 or 16 pages on 4 sheets. Have a look at where the blank pages end up; does this match what is happening in your document? (Adjust amount of blank pages depending on how many pages you fall short of a multiple of 16.)

NB: as you can see, [2*2*4] does not put page 10 and page 1 on opposite sides of the same sheet. In your question, however, you say (in the drawing) that they are. Are you sure this is correct?

== How \setuparranging[2*2*4] arranges 12 or 16 pages on 4 sheets. ==

First column:  Physical location
Second column: Each sheet side as it will be shown in a PDF reader.
Third column:  Like the second column, if a signature has
only 12 pages to arrange. [] signifies an empty page.

sheet 1 back   ----  16  01  --  []  01
sheet 1 front  ----  02  15  --  02  []

sheet 2 back   ----  14  03  --  []  03
sheet 2 front  ----  04  13  --  04  []

sheet 3 back   ----  12  05  --  12  05
sheet 3 front  ----  06  11  --  06  11

sheet 4 back   ----  10  07  --  10  07
sheet 4 front  ----  08  09  --  08  09


If it is indeed a problem of page amounts: the blank pages are to be expected. Either accept them; or provide content for them; or try to work out some way to arrange the last signature differently, which I personally would feel is more trouble than it is worth.

If the extra blank page does not follow the signature-with-too-few-pages pattern, it is probably time to remove bits of your document until you have a minimal working example that displays the problem.

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Yes you are right about that I wrote the wrong page number. On the backside of 10 is of course 9! Corrected this in my post. –  PetaspeedBeaver Mar 5 '13 at 21:49
! Thank you very much for providing some good thoughts about this. I will do more tests asap. I don't think it has to do with the total amount of pages since the blanks then should end up in the last signature, and now they're in the middle of the first. Will post here as soon as I have more results or a solution. –  PetaspeedBeaver Mar 5 '13 at 21:58

Human error close to the screen! :)

The problem had to do with an intentionally blank sheet (to later hold dedication) that in the unimpositioned document was at page 7-8. I had simply accidentally flipped this page of the signature over, making the pages appear still in the right order, but with the blank page at the wrong position (where page 11-12 should have been). Since I forgot that the to-become dedication page was still a blank (only \page[odd] \blank[7*line, force]) I didn't notice it was being generated.

Hope these posts will be useful to somebody else anyway. Big thanks for your engagement in my troubles!

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Hah, good to hear you solved your problem. Cheers! –  Esteis Mar 6 '13 at 11:58