In October 1946, the Hamilton Watch Company began manufacturing watch dials using melamine, a thermoplastic material that had recently been commercialized. Despite previous failures by other companies to produce a viable watch dial using thermoplastic technology, the Hamilton Watch Company concluded that melamine was a suitable substitution for enamel.
The new melamine dials were considered superior to conventional enamel dials according to every measurement. The new material was stainless and resistant to discoloration, allowing the watch dials to retain a brilliant white appearance. The surface was highly durable, especially when compared to the fragile glass enamel used on conventional dials.
Since melamine can resist heat up to 300 degrees Fahrenheit, the material was even being used to replace the enamel on gas stoves when Hamilton adopted it for watch dials.
Melamine can be baked at a lower temperature and cools much quicker than vitreous enamel, making the dials more efficient to manufacture. According to documents exploring the development of melamine dials, the company estimated that each dial would be $1.16 less expensive to manufacture when compared to similar enamel dials.
While all evidence at the time indicated new melamine material was a success, modern collectors know all-too-well the Achilles heel of the melamine material. Over time, the thermoplastic shrinks and expands continually until the surface develops fractures marring the dial.
Obtaining a surviving example of a melamine dial in excellent condition is becoming exceedingly more challenging.