When printing a PDF opened in a Firefox browser tab, the print job created is 2x-10x the size of one printed directly from Adobe Acrobat Reader. Not sure if this a rendering issue causing by Firefox producing an image instead of rendering it to the print spooler as text. In the attached image this does not look as pronounced (image created from Firefox 96.0.3 64-bit), but in Firefox 91.4.0 ESR & 91.4.1 ESR we have seen the difference between the PDF print job being up to 10x in size. This has caused printing of the same 10 page PDF to take 10-15 minutes vs 10-30 seconds. The size difference has been 13MB vs 700KB. Users are seeing the print job take much longer to get started and pauses between pages of up to 30-90 seconds depending on the content of the page. Obviously, details vary between PDFs. I have noticed that newer versions of Firefox do not appear to have as pronounced of a problem, so it may have already been fixed.