On a Zippo lighter, how often do you have to expose new wick?

I've been told that every so often on a Zippo lighter you have to pull the wick up and clip it so that some newer wick is exposed. Does anyone know about how often that is or when I know I should do that? Thanks!|||It all depends on how much you use the lighter, and how long you leave the lighter on at a time. If the flame you get is satisfactory, you need not change the length. Once the flame is too low for your liking, it's time to add some length. If the wick is frayed, and the flame is poor, you need to trim it and add length.|||i use matches...theyre more fun to set things on fire with..