Insert foldable A3 pages in an A4 document with active references

Question

I am at the end of a big LaTeX document (my thesis) and I would like to insert A3 tables and figures in the Annexes (Supporting informations) section. These A3 pages would be foldable and ideally I would like to have them page-numbered twice on the recto (so that ounce folded they look like single A4 page). Ideally they would be LaTeX-coded so that hyperref, inclusion in ToC and chemcompounds package (a package allowing automatic numbering of chemical compounds) would be active. Whould this be possible ? As a picture worth a thousand word, here it is :

Answer 1

Of course \pdfpagewidth must be declared somewhere before changing format, but there is no need to restore A4 settings, since the A3 ones are within an environment. On the other side the setting of \changepage are wrongly set; in facts the parameters of that macro must contain the difference between the original settings and the new settings therefore to switch to landscape A3 paper without changing the existing margins it suffices to write:

\changepage{}{210mm}{}{}{}{}{}{}{}

where 210mm is the increase of the textwidth due to the larger available horizontal page size.

Answer 2

I'm not sure if I fully understand your specifications for (some of) the appendix pages. I take it that you want the physical size of the appendix pages to be A3/landscape; the recto should be in two-column format, with each column given a separate page number; the verso, in contrast, should be in single-column format and not contain a page number (to judge from the images).

Assuming that this interpretation is on target, the layout requirement could be rephrased as stating that every third logical page in the appendix has to be in A3/landscape/unnumbered format. Assuming that you're fine with 25mm margins on all four sides of the large page, your objective could be achieved by (i) loading the afterpage and changepage packages in the preamble, (ii) creating a new environment called hugepage as follows:

\newenvironment{hugepage}%
  {\clearpage
   \pagestyle{empty}  % turn off display of page numbers, headers, ...
   \changepage{247mm}{370mm}{25mm}{25mm}{}{}{}{}{}} % switch to A3
  {\addtocounter{page}{-1} % decrement "page" counter variable by 1
   \clearpage
   \changepage{160mm}{247mm}{25mm}{25mm}{}{}{}{}{}} % back to A4

and (iii) adding the following code on the even-numbered (logical) page of the recto (physical) page:

\afterpage{%
\begin{hugepage}
... code that goes onto the huge page ...
\end{hugepage}}

Of course, the precise values of the arguments of the \changepage command will depend on the actual layout of your document (which you haven't stated, which is why I'm assuming for simplicity margins of 25mm on all four sides).

With this design, all cross-references will work as usual, including those to items on the un-numbered (verso) large pages. The only thing that's not going to work properly is the \pageref command to something that's on an unnumbered page... Hope this helps!