The canvas is underneath my screen shot, so it doesn't come into the equation here. I don't know how to take a screen shot of SnagIt, so I'll try to explain.
When using the Simplify tool I select the 'Left align text' option and drag over the fields I want to blank the text out on. In the Tool Properties there is an option for Fill, Shape, and Background. In this Background option there doesn't appear to be a transparent option. It is here that I need it, so the background of the simplified text doesn't cover over the field boxes.