
For the King Rama IX 3rd Series of definitive stamps, Thailand turned to the London-based printing firm of Thomas de la Rue & Company Ltd. after using Waterlow & Sons Ltd. for the two previous series. Perforated 13½x13, the 18 engraved stamps were printed on paper watermarked with a rectangular pattern, which looks like bricks to me. The first of these were released on July 1, 1961, and the last on February 1, 1968. The denominations and colors were as follow:
- 5 satang rose claret (1962); 4,000,000 printed (Scott #348)
- 10 satang green (1962); 13,000,000 printed (Scott #349)
- 15 satang red brown (1962); 4,000,000 printed (Scott #350)
- 20 satang brown (1962); 38,000,000 printed (Scott #351)
- 25 satang carmine (1963); 10,000,000 printed (Scott #352)
- 50 satang olive green (1962); 49,000,000 printed (Scott #353)
- 80 satang orange (1962); 2,000,000 printed (Scott #354)
- 1 baht violet blue & brown (1961); 2,000,000 printed (Scott #355)
- 1.25 baht red & citron (1965); 2,000,000 printed (Scott #355A)
- 1.50 baht dark violet & yellow green (1961); 4,000,000 printed (Scott #356)
- 2 baht red & violet (1961); 4,500,000 printed (Scott #357)
- 3 baht brown & blue (1961); 1,500,000 printed (Scott #358)
- 4 baht olive bister & black (1968); 2,000,000 printed (Scott #358A)
- 5 baht blue & green (1961); 3,500,000 printed (Scott #359)
- 10 baht red orange & black (1961); 2,500,000 printed (Scott #360)
- 20 baht emerald & ultramarine (1961); 1,000,000 printed (Scott #361)
- 25 baht green & blue (1961); 1,200,000 printed (Scott #362)
- 40 baht yellow & black (1965); 500,000 printed (Scott #362A)

Scott #348, 349, 350, 351, 352, 353, 354, 355A, 358A