Thai traditional lacque work comprises tow inportant skilled craftmen to work together. There are 'Chang Rak' (artisan of lacquer work) and 'Chang Khian' (artisan of painting).
At the beginning, 'Chang Rak' was in charge of making Rak lacquer vanish. However, in the later period. 'Chang Rak' had to practice lacquer vanishing and gold leaf gilding as well.
'Chang Khian' will sketch the patterns on the surface of and object, which is already covered with Rak lacquer or vermilion cinabar, and gild it with gold leafs. After that rinse the water through the object, and the detailed patterns or pictures are created in gold outlines. This technique is called 'Lai Pidthong Rodnam', which literally means to gild with the fgold leafs, and followed by pouring the water. The workd 'Lai Pidthong Rod Nam' was finally corrupted to 'Lai Rod Nam' (pattern of pouring water) or 'Lai Thong' (gold pattern). To create this type of artwork 'Yang Rak' is the most important substance.
The natural ingredient used to produce Rak lacquer is called 'Yang Rak' (Rak resin; melonorrhoea). It is originally from Rak tree (Melanorrhoea usitata). Similar ingredients are 'Yang Rak' (Rak latex) and 'Rak Nam Kiang' (Rak lacquer vanish). The other admixtures are 'Samuk' (paddy ash) or 'Rak Samuk' (paddy ash mixed with Rak lacquer vanish), soluble orpiment and gold leaf.
'Lai Pidthong Rod Nam' or Rak lacquer work can be dated back to Sukhothai Period as gold leaf gilding was applied to some bronze Buddha images.
In Ayutthaya Period, red background was popularly practiced at the beginning. However, in the late period, black background was more largely practiced. There was a sentence in an old document called 'Khamhaikan Khunluang Wat Pradu Songtham' (the Account of Khunluang from Wat Pradu Songtham), dated in the 19th Century, mentioned about "the wooden wall as decorated with 'Khian Thong Long Rak' (gold painting and Rak lacquer" and "the wooden wall was decorated with 'Lai Rod Nam Thong Kham Plaeo Phuen Rak' (pattern of pouring water, gold leaf giding and Rak lacquer)." The example of an architectural building of this period that presented lacquer technique was the column of the sermon hall at Wat Yai Suwannaram, Phetchaburi Province.