Fishing lines for crankbaits come in 3 basic types:
Optimal crankbait line in shallow water when fishing around structure such as rocks, underwater logs, trees, and related structure- fluorocarbon is good selection. It is tough, abrasion resistant, and holds up to the rough conditions. Braided line in stained water or dark water is a solid choice under similar conditions as well. Braided line is not as camouflaged as your fluorocarbon, but throwing cranks in dark stained water, it really doesn't make a difference.
Monofilament is the best fishing line for crankbaits when running baits into deep water. Remember that lighter lines will impact crankbaits to run your baits even deeper. Look at the manufacturer label for your crankbait and see what pound test line runs it how deep? Running a 1.5 pound difference lighter usually gets you another couple of feet in depth. Going a 1.5 pound test heavier will run the bait a couple of feet shallower. Knowing this, you can fish baits in a short order to the depth you are looking to target that are holding fish.
If you are looking for a monofilament that is generally good for most all conditions, I am very solid with green Berkeley Trilene for crankbait fishing line. However, fishing cover and getting nicks and abrasions in your line is the drawback, be prepared to strip line and re-hook when this occurs.