Cranks, jerk baits, and spinner baits are retrieved at higher speeds and the hooks on these baits are normally exposed. Ideally, reaction baits are thrown on a slightly more flexible rod. This is done to absorb the initial strike from the fish and allow time for fish to take a lure into its mouth. So in this case a bit of stretch from the line can be a benefit, as it does add to the shock absorption when using a reaction lure. So for reaction baits monofilament should be your first and most common choice. But as with all fishing there is an exception, light diameter fluorocarbon can be very useful on crankbaits, it will allow the bait a few extra feet of diving depth and added sensitivity can be very well applied in the hands of an experienced fisherman. Please note; some thought must be given to the absorption properties of the rod used when using fluorocarbon on cranks.