Today's modern cash register use thermal paper in two common sizes. Older registers use bond paper that also require an ink ribbon also in a very common size. The ink ribbons for a cash register are a little harder to track down these days although we do carry the most common models of cartridges. We warn against just buy the lowest price for a ten pack of paper as you quite often pay far more per roll or even worse you will buy a 10 pack of paper with hardly any paper on them. Look for rolls of thermal paper with at least 200' of paper on it or more. In bond rolls you want at least 150' per roll. The smaller rolls are cheaper because they have less paper on them. Those small rolls are designed for credit card terminals not thermal printing cash registers.