The ER-5240 used 2.25" thermal paper rolls in both the receipt and journal sides and because they are thermal this model needs no ink ribbon or roller. We suggest using a full size roll of 200' to 230' so you are not contactly changing the roll. The 2.25" thermal paper roll is one of the world's most common paper rolls because it is also used in so many credit card terminals too. Remember to keep paper in both side even if you don't issue a receipt.