POP or Plaster of Paris. But why is it of Paris, and not of Lagos, Tokyo or Los Angeles, you must have queried?
Rest easy, eager beaver. This article seeks to address your question and solve the mystery.
History of Plaster
Plaster is the common name for calcium sulphate hemi hydrate made by heating the mineral gypsum at temperatures of 140-180 degree Celsius. Gypsum is the common name for sulphate of lime.
Plaster was first made thousands of years ago, and was used by the ancient Egyptians, Greeks and Romans. However, it wasn’t used on a large scale until the 1700s when it was required to be used in all construction in Paris.
The Name, Plaster of Paris
In 1666, a fire raged across London, destroying many parts of it. In its aftermath, the King of France ordered that all walls made of wood in Paris be immediately covered with plaster, as a protection against such fires. This resulted in large-scale mining of gypsum which was available around Montmartre hill in Paris in huge quantities.
Thus, during the early 18th century (1701-1800), Paris became the centre of plaster production, and hence the name, Plaster of Paris.
Uses of Plaster
Plaster of Paris does not generally shrink or crack when dry, making it an excellent medium for casting molds. It is commonly used to precast and hold parts of ornamental plasterwork placed on ceilings and cornices.
It is also used in medicine to make plaster casts to immobilize broken bones while they heal, though some orthopaedic casts are made of fibreglass or thermoplastics.
Some sculptors work directly with Plaster of Paris, as the speed at which plaster sets gives the work a sense of immediacy and enables the sculptor to achieve the original idea quickly.
Finally, the mystery of the POP is solved! Pheew.
