Fogli grandi

Credo tu possa usare il pacchetto geometry o il pacchetto typearea. Puoi anche guardare il pacchetto/classe sciposter http://www.ctan.org/tex-archive/macros/latex/contrib/sciposter/
Dalla documentazione di sciposter:

6 Class Options
6.1 Paper-size options
In this class, paper sizes also change the default font size. The class options controlling paper size implemented within sciposter.cls are:
ISO A series:
a0 ISO A0 paper size (83.96cm × 118.82cm); normal font size 25pt.
a1 ISO A1 paper size (59.4cm × 83.96cm); normal font size 20pt.
a2 ISO A2 paper size (41.98cm × 59.4cm); normal font size 17pt.
a3 ISO A3 paper size (29.7cm × 41.98cm); normal font size 14pt.
ANSI Sizes:
ansiE ANSI E paper size (86.36cm × 111.76cm); normal font size 25pt.
ansiD ANSI D paper size (55.88cm × 86.36cm); normal font size 20pt.
ansiC ANSI C paper size (43.18cm × 55.88cm); normal font size 17pt.
tabloid Tabloid, a.k.a. ledger, a.k.a. ANSI B paper size (27.9cm × 43.18cm); normal font size 14pt.
This version also supports “external” paper-size specification, through files which have names of the form paper.cfg, e.g. paperb0.cfg for ISO B0.
ISO RA series:
ra0 ISO RA0 paper size (untrimmed A0: 86cm × 122cm); normal font size 25pt.
ra1 ISO RA1 paper size (untrimmed A1: 61cm × 86cm); normal font size 20pt.
ra2 ISO RA2 paper size (untrimmed A2: 43cm × 61cm); normal font size 17pt.
ISO B series:
b0 ISO B0 paper size (100.0cm × 141.4cm); normal font size 30pt.
b1 ISO B1 paper size (70.7cm × 100.0cm); normal font size 25pt.
b2 ISO B2 paper size (50.0cm × 70.7cm); normal font size 20pt.
b3 ISO B3 paper size (35.4cm × 50.0cm); normal font size 17pt.
Custom Sizes:
custom Edit file papercustom.cfg to specify any type of paper (see below).