I think if you are going to use Florocarbon line, use the highest test strength you can get away with for the type of fishing you are doing. If you are drift fishing and normally use 8 lb test, step up to 10 or 12 with Florocarbon....after all invisable is invisable...The invisable man is still invisable whether he is fat or skinny, just don't step up to a higher #lb test thickness that would impeed the action to the type of fishing you want to do.