making a rectangle outline for a sign

I use Inkscape to draw images that we cut out on a CNC plasma table. What I'm trying to do should be simple but I can't seem to figure it out.

I am making a sign that has text in it and I would like to have a rectangle border. So I have the text, I use the rectangle tool to make a border and while I view in outline the rectangle is visible but when in normal mode is gone. I really don't care that it isn't visible what the real problem is that my plasma program can't see the outline.