Hi Pam
That sinus infection sounds nasty. Hopefully that does explain the headaches though ... in which case then the antibiotic will help with those too... would be nice.
Reason I asked about the ribbon is it would indeed be hard freehand. But I thought you might sort of stencil it. Still tedious to do this, but perhaps slightly easier/not as risky, and possibly with a sharper result. You could cut out squares of masking tape or plastic packing tape, and stick them onto the ribbon in your checkered pattern. Then slather on the paint, then remove the tape.
I don't know if you'd want to do that, or if the type of paint you are using would work (if it's a plasticky type, then peeling off the tape might take some of the paint with it). And I know you've got to be pretty precise with a brush given your nailwork, so maybe freehand will be the easier thing for you.
Anyway, just figured it wouldn't hurt to say.