Answer:
"The number of times that you'll need to apply gesso and then sand it depend on how smooth and absorbent you want your ground to be. Basically, the more layers of gesso that you have, the better the paint will "stick" to the surface. It can also enhance the luminosity of a piece. In my opinion, painting on a well-gessoed surface is an absolute dream!"
Step-by-step explanation:
"With that said, typically you'd only need to gesso and then sand 2-3 times if you want a really smooth, absorbent surface. If you want, you could try an experiment by gessoing and sanding your surface 4-5 times (or more!), to see if it makes any noticeable difference for you. That way you'd really know for sure how many layers of gesso you prefer."