Font looks blurry, not sharp

[Piezzzii Tre]

Hi there,

first I would like to thank the developers for this software. With this, I'm able to convert images of scan books into a pdf format for me to read and highlight text on the mac! Thanks!

But ever since I've upgrade my Mac OS to 10.12 from 10.8. scantailor seems to behave stranger. When I output a image text after going through all the steps 1 - 5, my text on screen is never sharp, instead it's totally blurred. This has never happened to my on the older os. Of course it only happens when I increase to thicker size, then it gets blurry.

Is there something wrong? Can anyone advice me how to fix this problem?

I'm using 2013.04.30 version of scan tailor.

best