Printing device using two printing parts and a reading sensor for continuous printing

A printing device comprising a printer having a first printing part, a second printing part, and a reading sensor, the printer continuously printing plural pieces of printing data onto a printing medium, the first printing part in the printer first printing the plural pieces of printing data onto the printing medium by forming a mark indicating each of the plural pieces of printing data, the reading sensor subsequently reading the mark and matching printing surfaces of the printing medium to be printed by the first and second printing parts, the second printing part in the printer thereafter printing the plural pieces of printing data onto the printing medium, the printing device comprising:

• an information holding part which previously holds information on a relationship between the size of the plural pieces of printing data and a position of the mark;
• and
• a mark position setting part which movably sets the mark position based on the information held in the information holding part in accordance with the sizes of the plural pieces of printing data.