I found a good tape for sealing hinge lines at the Dollar General store. It is their store brand clear packaging tape, and costs as you might guess, one dollar. It is quite thin and flexible, but it is two inches wide. You can roll some on to waxed paper, and with a straight edge and exacto knife rip it down the middle, or any width you like. Peel it off the waxed paper, and install it.
Don Jones