Single color reversible temperature indicator

A printable ink for reversible thermal indicators comprising:

• microcapsules retaining therein a core material that is opaque as a solid and transparent as a liquid;
• and
• a binder and a rheology modifier as a carrier for the microcapsules;
• wherein the microcapsules retain the core material therein for repeated, reversible transitions from solid to liquid and liquid to solid;
• wherein the binder and the rheology modifier are the same substance or are different substances;
• wherein the core material comprises:
• a phase change material mixed with a nucleation aid;
• wherein the nucleation aid reduces supercooling, thereby the core material becomes solid reset at a known temperature, and is selected from one or more of hyperbranched hydrocarbon polymers, fatty acids, microcrystalline waxes, isoparaffins, polyethylene waxes, and combinations thereof.