Possible Issues with Text
To change attributes for only one word of text in the edit box, it is not enough to use Object Inspector settings. You have to split single object into several text objects and set font attributes for each one of them.
When trying to edit text an error occurs: «This font doesn’t contain these characters. Try choosing another font.»
This happens because of PDF format specialty. When saving PDF file, the application embeds all used characters of the font into that file. However, it doesn’t embed not used character, so if you use font, which was embedded earlier, you can choose characters of a limited set.
For example, if you use Arial font to write a line “12345” and then save PDF file, only these 5 characters of Arial font will be embedded into file. If you open it and try to input another character (like “6”), you’ll see a message about absence of this character in the file.
A simple workaround for this kind of issue is to use Object Inspector to change font family for text object you’d like to edit.
Master PDF Editor has Automatically change font when editing text option in Settings > Editing tab. It works if current font (Arial in the sample above) is installed in the system.