# Making a centrefold figure

I'm laying out a 16-page booklet that has a two-page MetaPost figure spanning the centrefold. The intention is that the centrefold is "outside" the flow of the text: the image is always on pages 8–9, while the text from page 7 continues on page 10. However, it's really not important that it's a figure: it could be arbitrary text in the centrefold and the problem would be the same. It's having the centrefold skipped by the normal text flow, while still having fixed content, that is the problem.

Currently, my prototype is doing this by brute force:

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Duis eu ultricies ipsum. Morbi in nibh varius metus viverra
condimentum sit amet eu sem. Nulla facilisi.

% break this section manually to make the centrefold work…

% start the centrefold
\page[8]
\setupfooter[state=stop]

\setupbackgrounds[page][background={centrefold}]

\page[10]
\setupfooter[state=start]

% …and continue with the rest of the section

Vivamus tincidunt bibendum dapibus. Maecenas sollicitudin
arcu ornare arcu pellentesque suscipit.


I'm trying to generalise this into a template for a project that will have several similar documents. There must be a better way! Mustn't there?

I've approached the problem from a few angles, but haven't made any headway for lack of knowing the codebase well enough to know what's possible:

• "Can a float be forced to appear on a certain page? Hmm, not that I can find…"
• "Can I insert a page retroactively into the pagination? No commands I can find. Could do it in Acrobat, but yuck…"
• "Can I use buffers and measures…? I really don't know where to start with that idea."
• "Can I suspend normal layout at the end of page 7, execute arbitrary commands, and continue layout? No idea…"

I'm aware that often with a high-level problem like this might be many solutions using completely different combinations of ConTeXt's features. I'm just unfamiliar enough with the fine details of the available commands to know the one feature that I could build this around.

To compound the problem, I have two additional constraints and one possible saving grace:

• I have to have the text that flows across pages 7 and 10 split between paragraphs – I can't have a paragraph spanning the interrupting centrefold pages. I figure that's likely a separate problem, but given that I've no idea how the page interruption could be accomplished, I figure it deserves mention.
• I'm stuck using MKII for the time being for this document. However, if the only possible solution is a MKIV one, I could shelve this project until there's time for converting it to MKIV.
• The saving grace is that the section that needs to flow from page 7 to page 10 always starts page 7 and always ends on page 10. That might simplify a solution, as a solution doesn't need to be generalised beyond these four pages of the document. If I could hardcode "any text overflow from 7 goes to 10, figure starts on page 8" then I'd gladly do it.
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Search for \startposponing –  Aditya Oct 6 '12 at 0:36
@Aditya Make that an answer and I'll accept it! \startpostponing has some unexpected behaviours (uses absolute page number, not display page number; \setupfooter doesn't appear to work inside it), but it's exactly the sort of thing I was hoping for and I think I can work around those problems. –  SevenSidedDie Oct 6 '12 at 1:38
@Aditya Can you cook up an answer for this to get it off the list please ? –  percusse Dec 2 '12 at 0:12
@percusse: Will do so tomorrow. –  Aditya Dec 2 '12 at 5:52

As I had said in my comment, the main idea is to use \startpostponing.

To illustrate the idea, I'll work with a four page booklet with the center spread on page 2 and 3. (It does not look pretty when displayed below, but neither does page 8-9 on a 16 page booklet). Notice that the paragraph at the end of page 1 has not completed, and continues on page 4. The solution works with both MkII and MkIV.

\definestartstop
[centerfold]
[style={\switchtobodyfont[100pt]}, color=red]

\startpostponing[2] % Display on page two
\startcenterfold
A really big
\page
figure
\stopcenterfold
\page
\stoppostponing

\starttext

\dorecurse{5}{\input knuth \endgraf \input ward \endgraf}

\stoptext


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Excellent; this makes for nice clean code. (Since I'm doing imposition in the page layout, the centrefold does look quite pretty in the PDF output, too.) –  SevenSidedDie Dec 4 '12 at 1:38