Hi @thearabbit and sorry about that.
Improving the PDF export quality has been on our list for a while and our next major Desktop version will introduce high-resolution exports with selectable text. It’s already available in Balsamiq Cloud, our new native web version.
For now, the setting that will result in the best quality in Mockups 3 for Desktop is the Optimize for viewing on-screen option, as shown below.
Hope this helps! Any questions, we’re here!