First, it is considered less than 15cm, so you could be stupid enough to go without. In putting on tape, the first piece should go to just below the screws for two reasons, you only have to remove the small piece to get at the screws and it helps hold the barrel tight. Also if you have a German style tip (screws stick out) put a VERY small piece of tape to cover and protect just the screws and then the last piece.

On types of tape avoid Athletic, Electrical, Tiger and Duct tape for the same reason, too much glue that migrates. Fencing tape is the best, it is the right side, protects and has good glue properties, BUT IT IS WAY TOO EXPENSIVE. As said before, Gaffers,Hockey, Tennis are some very good alternates. Baseball tape can be too padded.