Kwenio

Hello, I'm Using Paint net to make a card for the birth of my first child. I got most of the things the way I want them. Just found out how to have editable text by installing tools. Now for the problem. I would like to put some of the text in bold and other parts normal. The tools I've tried only give me the option to put all my text bold or none. Does anyone know an easy solution for this? Or know of a tool that allows this? Thanks a lot in advance