GOP lawmakers are pushing high-tech ‘fraud-proof’ ballots. A Texas company could be the only supplier.

Holographic foil. Special ink designed to be sensitive to temperature changes. Nearly invisible “stealth numbers” that can be located only using special ultraviolet or infrared lights.

Those are among the high-tech security features that would be required to be embedded on ballots under measures proposed in at least four states by Republican lawmakers — all promoters of false claims that the 2020 election was marred by mass fraud — in an attempt to make the ballots as hard to counterfeit as passports or currency.

But the specialized inks and watermarks...