Embroidery Library offers this free pattern with excellent detailed instructions to add an embroidery design. The bottom section will be created with the large piece of paper. I used the 5. You can adjust the height by making the bib longer or shorter see below for instructions. This process is a very simple way to mass produce adult bibs for charity or a relative.
If you want the bib to be longer or shorter, adjust how long these lines will be. Spray a piece of medium weight cutaway stabilizer with temporary adhesive and smooth the fabric on top. You'll need a pattern or need to draft a pattern but the process used to make this apron is well worth your time.