What causes a blade to be good for flicks. Is it use or age? Make? Do they make blades flimsy for flicks? I've seen blades advertized as 'flicking' blades. Yet i have a few old ones good for flicking as well. I bought 3 blades from a retailer and they all felt different from stiff to flicky. If they make flick blades, are they easier to break? more expensive? or worth it?