Knowledge about the amulets of the U-Thong Period:
The main amulet which is believed to have been made in the U-Thong Period is the Phra Pong Supan, which is ranked as one of the Top 5 Amulets. Phra Pong Supan has the artful characteristics of the U-Thong Period, and was made of holy clay as it’s main material. This fine grained clay was infused with herbal liquids, while other herbs and flowers were ground into a powder which together were blended into a special mix that caused these clay amulets to dry particularly hard creating a smooth and shiny surface.
Phra Pong Supan Amulets were first found at the main “Prang” or Pagoda of Wat Phra Srirattana Mahatal in Supanburi by Chinese immigrants who were trying to farm vegetables around the Prang, when they encountered a number of sunken earth holes with amulets of various sizes and varieties including the Phra Pong Supan.
Later, in the year B.E. 2456 (A.D. 1913) the Supanburi ruler presented most of the amulets found there to King Mongkut, whom in return distributed them to his officers and followers. Phra Pong Supan also was said to have been made by 4 Hermit Gurus who composed the materials and minerals for the mix, then pressed to the mold by finger leaving finger prints behind on the back side of the amulets. The Amulets where bake in a kiln result them to have different colors from light tan, brown, gray, and some rare black, depending on the heating period and their position in the kiln.