Borderless virtual printing with CUPS (& Samba): PPD needed

[holgi1789]

Hi everybody,
I made a virtual PDF printer (with cups-pdf and also with cups and a new shell script backend) to generate PDFs from Windows machines.
It works good but the PDF has a small border. I think it is because the physical printers cannot print borderless.

I tried
Adobe PDF 3016.102 and
Generic postscript color printer rev4

Do you know a valid Postscript PPD to make borderless and A3 PDFs or am I completly wrong and it hast nothing to do with the PPD?

Thanks,
Holger