Preferably a 100W soft white incandescent bulb, but 60W or even 150W will also work. The lights need to be set up equidistant from where the artwork will be mounted (see illustration). They also need to be the same distance from the wall.
What Sells Best On Shutterstock?
Some types of photos that sell best are Portrait Photography, Food Photography, Landscapes (usually with people) and fine art photography (artsy).