[X-Newbies] Printer Drivers

[Chris]

Hi all,

I need to create a pdf ready to print at A1 size at a bureau.  My own
printer is only A4 so the obvious way is to use a printer driver for an
A1 printer - say an HP DesignJet and use that to save to pdf.  

Does anyone know if this will work, or are there any other ways of doing
it?  I should add that I've tried creating a custom paper size but my A4
printer just tells me it won't do it - even to save as pdf.

cheers,

chris