King Ramkhamhaeng the Great created the ancient city of Sukothai in the 13th century and references to Thai pillows have been found in inscriptions within its ruins. Therefore it’s reasonable to assume that these pillows were well established in Sukothai during this period.
Because Sukothai was a major trading center, Thai pillows likely incorporated Chinese and Indian designs. The Chinese triangular pillows were made from wood or clay and used as neck supports, whereas Indian triangular pillows were made from stone and used for yoga and meditation.
The popularity of these cushions continued during the Ayutthaya period (1351-1767). Relics have been found of cushions decorated with intricate carvings and designs which, it is believed, were used as seating cushions for high-ranking individuals. Today it is more common to see cotton, silk, and kapok used to make pillows, responding to the demands of the modern market.https://thaihomeshop.com/blogs/news/thai-triangle-cushion-matress-pillow
