Empty lines (HTML P tag) take space in PDF not in print and e-mail

I use this module to print a webform conformation page that contains webform submitted fields. Some lines are empty, like
<p> </p>
These are webform options the user did not select.

In the print and e-mail output all these empty lines lay on top of each other, so they don't take space.
But in the PDF output every line uses it's own line height, creating lots of blank lines.

I use the TCPDF library.

How do I get the same lay-out in PDF as in print and E-mail?