I will add this to Nikka's thorough list.

1. Thick leather belt - pain factor 5-6 (using Nikka's scale). If not doubled it will cut the skin. Doubled it can bruise. leaves large welts.
2. VInyl braided belt- Pain factor 6-7. Same rules as the leather.
3. Three stranded whip with very thin long hard leather strands- (woodsman's favorite) Sharp stinging sensation. (6-7) (depends on how it is used) Because it is long it wraps around the body and the ends leave v shaped small bruises. Careful with this one; the marks last a long time.

The sensation of the whip and belt are quite different. I really dislike the stinging sensation of the whip. That's why I rate the pain high, but someone else might not feel that it is as bad as the belt.