Refilling of INKEDIBLES brand edible ink cartridges is easy to do. Inkedibles cartridges have a premade refill port (hole), so filling the cartridges is as simple as: 1) Remove the sealing plug from the refill port 2) Fill with edible ink (using the syringe included in this pack) 3) Reseal the refill port with the sealing plug or a new sealing plug Inkedibles brand edible ink cartridges also come with auto-resettable chips, which means they can be refilled over and over and the printer will keep recognizing them as full. However, most edible ink cartridges should be refilled 2-3 times at most before replacing them with a new Inkedibles edible ink cartridge, because quality can deteriorate over time as the cartridge wears out and becomes less efficient at dispensing the edible ink. Note: The syringe refill tip included with this syringe pack is blunt (not sharp), for safety reasons, and should be used only as intended to refill the Inkedibles edible ink cartridges.