Never mind, I found the solution.

With the pdf attached, this command work :
$> pdfposter -p4x2a4 qqout.pdf ww.pdf

I obtain the pdf by "print as pdf" from inskape.
And it's A1 format here

Thanks

Dear All I'd like to create a poster composed of multiple A4 pages. So I created an A0 document and now I try to print it. I don't find any options to make Inkscape print automatically multiple pages. So I tried to print on PDF and then to use pdfposter, but I'm not able to set correct values. I'm w...