Re: plain TeX: different \hsize and \vsize for odd and even pages (was: plain TeX: different margins for odd and even pages)

On 8 Apr 2026, at 19:42, Rodolfo Medina <[email protected]> =
wrote:
>=20
> Rodolfo Medina <[email protected]> writes:
>=20
>> [...] suppose I want to set different margins for add and even pages, =
say 5mm
>> left and 10mm right for odd pages and the opposite for even pages: =
please
>> suggest whoever can a proper way to do it.
>=20
>=20
> Solved that problem with listers TeX-perts' help, now suppose I want =
to do the
> same with \vsize and \hsize, i.e. set a different \vsize (and/or =
\hsize) value
> from odd to even pages: is it possibile?  I mean in `pure' plain TeX.

I can offer the following hack:

\toks0\expandafter{\plainoutput\adjustvsize}
\edef\plainoutput{\the\toks0}
\newdimen\oddpagevsize  \oddpagevsize=3D... % insert desired value here
\newdimen\evenpagevsize \evenpagevsize=3D... % and here (instead of ...)
\def\adjustvsize
  {\global\vsize=3D\ifodd\count0\oddpagevsize\else\evenpagevsize\fi}
\adjustvsize % for the first page

It works, at least on simple examples. But it may not be very robust.

=E2=80=93 Harald=