I have noticed on some pages that the text is not vectorized. Why is that?

There can be a few reasons for this. Most of the time, this occurs if the text in question is part of a bitmap graphic on the PDF page rather than having been added as embedded text on the PDF document. images cannot be vectorised. Only text that has been embedded on the PDF document can be vectorised. If you are sure that your text has been embedded on your PDF document but your text is not being vectorised and looks blurry, please send our support team your PDF file and mention where the problem occurs so we can investigate further. Our support team can be reached at support@3dissue.com.