The characteristics of this series were similar to those of the 4th series printed by Thomas De La Rue & Company Limited and the Royal Thai Survey Department, except the portrait which was King Rama IX. There were 6 denominations: 50 satang, 1, 5, 10, 20, and 100 Baht. Each denomination had many types. They had been issued in 1948. As the 9th series had been circulated for over 20 years, people were quite familiar with the colors of each type and denomination, making them difficult to change. Therefore, it can be assumed that the colors of the 9th Series are the standard for current Thai banknotes.