A white backdrop is three different backdrops depending on how much light reaches it. Before a shoot we agree which one we are making, because it changes the lighting plan and the time it takes.
Clean white
Two lights on the background, a stop over the subject, and the subject far enough forward that the spill does not wrap them. It is the e-commerce look and it needs the most space.

Soft grey
Turn the background lights off and let the key fall away. The same white paper goes grey behind the subject, and the portrait gains depth for no extra time at all.
White as a room
Open the windows and let daylight do it. The backdrop reads as a wall in a room, not as paper, which is often what a brand means when it says it wants something natural.
