Thanks mitch. I can do what you suggest when simply writing text to the drawing, writing with 0.08mm text and successfully making that the default.
Problems arise, though, when I use the smart dimension tool or the horizontal or vertical dimension tools. I can go through the same sequence for setting the text size for use with these tools - but every time, the size drops back to 0.000. Not surprisingly, no dimensions appear when I try to add dimensions to my drawing. Is there some step I'm missing?
I attach my current draft drawing, in case there is something about the drawing that causes the problem.
Another problem i'm having is in saving and printing pdfs of my drawing. I'll raise this as a separate thread, if necessary.