When print or save as PDF the font size is too large

Question

When I print or save as pdf the font size is too large

I have printed the whole notebook to pdf or saved it to pdf, but the font size was too large, and I have set the PrintingStyleEnvironment -> "Printout" , and I have set the magnification of printingoptions is 0.5,but it doesn't work, and the font size is still big, so how to only adjust the pdf font size?

I have tried

SetOptions[$FrontEnd, PrintingStyleEnvironment -> "Printout"]
SetOptions[$FrontEndSession, PrintingStyleEnvironment -> "Printout"]
SetOptions[All, PrintingStyleEnvironment -> "Printout"]
SetOptions[Notebook, PrintingStyleEnvironment -> "Printout"]

Cell[StyleData[$FrontEnd, "Printout"],Magnification -> 0.8]
Cell[StyleData[$FrontEndSession, "Printout"],Magnification -> 0.8]
Cell[StyleData[All, "Printout"],Magnification -> 0.8]
Cell[StyleData[Notebook,, "Printout"],Magnification -> 0.8]

But it doesn't work, so how to realize it?