A customer recently reported a problem with the font "Tahoma", which is set to italic and is displayed correctly in italic in the VPE preview, but in the created PDF document, the font is displayed non-italic.
The cause is that there does not exist an italic version of the "Tahoma" font. Windows synthesizes the italic representation, but PDF does not do this. It is possible to write some PostScript instructions into the PDF stream, so that it is synthesized there, too. But this is not implemented into VPE and a complex task within the current code structure.
Solution: open the directory "Windows\Fonts", so you can see the complete list of installed fonts on your machine. You will also see for what fonts italic versions are available, which is for most fonts the case (for example "Arial" and "Times New Roman"). Do only use italic with fonts, which provide an italic version.
Note: the same problem applies to bold fonts. A bold version of the font must exist.