Is it possible to set the z-order of the watermark?

[lirm-math]

I use the pdfpages package to produce new PDF files from some existing PDFs, and I use draftwatermark to add page numbers to each page. I found that on some pages the page numbers are covered by the content of the original PDF, which consists of images generated by scanners.

My question is that if is it possible to set the z-order of the watermark, so that it covers other contents, instead of being covered?