Problems with the actual measurements in pcb printing

Hello everyone
Forgive my ignorance but I tried to solve my problem also crecando on the old forum and in the instructions fritzing.Il my problem it is that when I export my pcb in pdf all the actual measurements including the pin dip spaces , and pin headers are more piccoli.Ho tried every setting and modification of measures but the result is always the same .

Thank you for your attention and forgive my bad English

Could it be that the printer rescales the image to ‘fit’ on the page.

do you use the pdf, png, other? what dpi setting is used?