A printing device includes a paper roll carrying base and a distance sensor. The paper roll carrying base includes a paper roll accommodation space and two paper clamping arms. The two paper clamping arms are opposed to each other and installed in the paper roll accommodation space. A paper roll is clamped by the two paper clamping arms. The distance sensor is disposed on a bottom surface of the paper roll accommodation space. The distance sensor faces the paper roll. A paper roll distance between the paper roll and the distance sensor is detected by the distance sensor. A remaining amount of the paper roll is estimated according to the paper roll distance.

A printing device includes a paper roll carrying base and a distance sensor. The paper roll carrying base includes a paper roll accommodation space and two paper clamping arms. The two paper clamping arms are opposed to each other and installed in the paper roll accommodation space. A paper roll is clamped by the two paper clamping arms. The distance sensor is disposed on a bottom surface of the paper roll accommodation space. The distance sensor faces the paper roll. A paper roll distance between the paper roll and the distance sensor is detected by the distance sensor. A remaining amount of the paper roll is estimated according to the paper roll distance.

An image forming system includes a sheet holding apparatus and an image forming apparatus configured to form an image on a sheet conveyed from a sheet holding unit of the sheet holding apparatus. The sheet holding apparatus includes a display unit. The display unit is configured to, in a case where an amount of sheets held in the sheet holding unit decreases to a first amount before execution of a job is completed, issue a notification using a first notification method, and in a case where the amount of sheets held in the sheet holding unit decreases to a second amount smaller than the first amount before the execution of the job is completed, issue a notification using a second notification method.