Why, exporting a PDF, inkscape changes the font of the text?

How can I avoid it?

Thanks in advance

Not sure on this, but could it be because you do not have the font used in the PDF installed on your computer?

EDIT: Realized that the above would only apply if the PDF was something you imported and then re-exported...

you are right. I import a PDF file, then i draw on it and, finally, I export it.

Is there a way to avoid the font's changing?

Well, you have to have the font the PDF uses installed on your computer. You could go to What The Font and try and match it, but it is likely the font is NOT freeware...

EDIT: Oh wait, have you tried disabling the "Import text as text" option when you import the PDF? That might work.

Hi SureWhyNot...

Thanks for helping me! I discover my error.
The changing of the font happens when you try to export a PDF via CAIRO ... BUT .... now I'm doing in this way: I print the file choosing PRINT TO FILE and I create a PDF file. In this way It works without font's changing and with a perfect graphic's quality.