Marks depend on two things... the force of the action and the type of flesh you have (and where you have it). You can welt and bruise from a licorice stick, if you have enough force and tender flesh. For instance, I don't bruise easily. Though, I bruise on my legs more than my tits. And, my Master is VERY harsh. But a lighter touch or more tender flesh (even the color flesh) will make a difference. As a general rule, canes usually do pack a punch. But, it all really depends on those two things. My advice, start out slowly and less rough and work your way up to a doable point. And then make note of it for next time. And, that doesn't just pertain to bamboo canes, that pertains to just about everything.