It turns out that the the design is modeled after a pumpkin or gourd.  Maybe in ancient times, gourds were used to carry water and this design stuck. These water jugs have been used in Malaysia for a very long time and, because of that, no doubt the style went through a series of refinements.

It is perfect for keeping water cool without refrigeration. the black jugs are made with gray clay. Another source said the pieces are first smoked, then burned, then rolled in rice husks.

It is believe that the water stored in Labu Sayong help prevent many illnesses and stomach disorders. No research has been done on this medical value. Anyway, it is very important to drink lots of water each day.

There are numerous Labu Sayong Enterprises in Kg Sayong, Kg Bukit Lada, Kg Pauh, Kg Sayong Ketengah and Kg Kepala Bendang approximately 15 kilometers from The Royal Town of Kuala Kangsar from the Northern State of Perak, Malaysia. The Malaysian Government is promoting this Cottage Industry as part of their SDSI (Satu Daerah Satu Industri) program literally translated as One District One Industry. The Perak branch of the Malaysia Handicraft Development Corporation has opened a Handicraft Centre at a nearby town of Enggor which offers a training course in the making of Labu Sayong apart from selling these useful and attractive products.

According to www.leisuretoursmalaysia.blogspot.com and www.janestreetclayworks.com