500 Baht - Rama IX Princess Mother

P#95 was issued to commemorate the 90th birthday of Princess Srinagarindra, the Princess Mother and mother of Rama IX, born in 1900. A commemorative issue rather than a standard circulation series replacement, it sits outside the typical progression of Thai banknote series and was printed entirely in-house at the Bank of Thailand's own facility — one of the few central banks in Southeast Asia with full domestic printing capability by that period.

The watermark is the sole mechanical security feature, modest by 1990 standards. Circulation examples showing handling wear are considerably more common than might be expected for a commemorative — Thailand did not withdraw the notes from general use.