Hello Frédéric, Thunder T, Heejoo Ham and All,
You should have a look to the valuable post of ItzBobWright, one year ago, about the printing font size problem, described in the first part :-)) Refer to the link, below :
https://notepad-plus-plus.org/community/topic/14/printer-font-size-modification
The second part, relative to a way of updating a configuration file, in the %AppData% folder, may, also, be useful !
Cheers,
guy038