Just a preference.
For any beginners who may be reading this, the effect is very simple to achieve. You just need a background a bit darker than your subject. You need your subject front lit. and you need to expose for the subject and let the background fall off to dark. Some of these backgrounds are almost pure black as shot but when I run the Raw file through DxO they lighten up more than I would like so it takes some work to get them back.
