Printing multi-color images on non-vinyl plastic identification documents in identification document printing systems. A non-linear pixel density adjustment curve is used to adjust the pixel density data of a multi-color image to be printed which adjusts the power applied to the thermal print head. The use of a non-linear pixel density adjustment curve to adjust the pixel density data improves the quality of the resulting multi-color printed image, reduces mass transfer of the dye donor layer, and reduces breaking of the carrier film of the print ribbon.

According to some embodiments, a gaming system includes a first shaped game piece capable of receiving a reversible pigment and a second shaped game piece capable of receiving a reversible pigment. The first shaped game piece and the second shaped game piece comprise a same shape and the reversible pigment comprises a thermochromatic pigment.

A digital printed fabric includes a base cloth and a digital printing ink disposed on the base cloth, and a manufacturing method for the digital printing ink includes the following steps. A first thermal process including mixing a dye, a crosslinking agent, and a polyol is performed, such that a polymer dye is formed, in which a reaction temperature of the first thermal process is between 70 C. and 90 C. A second thermal process including mixing the polymer dye and an aqueous bridging agent is performed, such that a first mixture is formed, in which a reaction temperature of the second thermal process is between 90 C. and 120 C. A third thermal process including mixing the first mixture and a chain extender is performed, such that the digital printing ink is formed, in which a reaction temperature of the third thermal process is between 120 C. and 150 C.