Abstract: Different print sheet sets are disclosed to receive printing by a thermal printer. A thermal image transfer sheet is removably attached to a print sheet having a score line across the same to form a zone for coded indicia and a zone to receive printing. Indicia are provided in the indicia zone to represent certain conditions, such as the optimum thermal printing energy to be applied to pixels forming a printing head, and such indicia are sensed by a sensing device to program various aspects of printing, such as the printing format. The print sheet may be divided, as by scoring, into different print fields so that it may be readily separated into separate display signs.