The Samsung ER-4940 uses 44mm bond paper rolls and an ERC-18 ink ribbon cartridge. Please remember it is not a good idea to operate this register without paper or ribbon. If you don't want to issue a receipt simply turn it off but don't remove the paper. Never re-ink the ribbon, when ink becomes faded replace the ribbon with a new factory inked cartridge.
The ER-4940 is one of those old school cash registers with a receipt and journal printer. The purpose of the journal is security and auditing. the journal prints every transaction as it happens and should not be confused as the "End of Day report" as cash registers produce that on demand rather you have a receipt and journal or the receipt only.