Melissa,
Handpainted
signs are a typically high quality, one of a kind creation and are purchased from highly skilled
sign makers. They will have a certain handcrafted look that is hard to explain or duplicate by machine. You need to look at a few and compare them to really understand. The downside is it is not reproducible in the same way as wide format printing. If the
sign maker retires or otherwise goes out of business you have to find someone else with the same skills to reproduce it.
Wide format printing is still good quality but lacks the handcrafted look. It is stored in a digital file that may be able to be used by many other
sign makers on similar printers and get the same results. The art can be resized and reprinted again and again.
Hand painting is for that customer that really wants the hand-painted look. Often with a retro style and is willing to risk the problems of reproduction later. These are restaurants, retail stores and sometimes contractors with one vehicle.
Wide format printing is for that customer who wants to reuse the image again and again in different sizes with flexibility. The disadvantage is the longevity of the image which is usually less than handpainted. Most customers are in this second group. Thankfully there are a few of the handpainted customers out there to keep the craft alive.
I hope this is a little more helpful but keep in mind these are generalities.
Tim