Variations on plaster of Paris have been used for millenia in construction, medicine and art. It is used a finish on walls and ceilings and also for mold making and sculpture. Until the mid-20th century it was used to set broken bones. The existence and use of plaster of Paris in the modern world is deeply tied to our ancient roots.

What Is Plaster Of Paris?

The term plaster of Paris was first used in the 1700s due to large quarry deposits of gypsum located in Montmartre, a district of Paris, which was a leading center of plaster at the time. Plaster of Paris has become a generic reference that is used to describe any plaster that is a mixture of calcined gypsum (calcium sulfate dihydrate), sand and water. When these ingredients are mixed together and the subsequent paste is allowed to dry, it hardens and forms a tough coating. As tough as plaster of Paris is when dry, it is still soft enough to be sanded and carved.

Early Uses of Plaster of Paris

The Giza Collection at the Museum of Fine Arts, Boston, houses diaries and publications that are dotted with information about the plaster walls and artifacts, still intact and durable, found in the interior ruins of the Great Pyramids. Peter Roger and Stuart Moorey reveal in their book "Ancient Mesopotamian Materials and Industries" that plaster vessels have been found in excavations of Ur (dating around 3000 B.C.E.) and Tel Brak (as early as 6000 B.C.E.) that appear to be designed for carrying dry ingredients. The fire preventive properties of plaster were known and used in Paris in the 17th century, when plaster of Paris was used to coat wooden structures.

Plaster Casts

The invention of the plaster bandage can be attributed to an Arabic doctor and is noted in the Al-Tasrif, an Arabic medical encyclopedia dated from around 1000 C.E. This earlier adaptation of plaster for orthopedic cast making was unknown by European and American doctors. The use of plaster of Paris in the modern medical field began in earnest during the 1800s. By the 1850s bandages were rubbed with a plaster of Paris powder and then dampened and applied around the injury. During the 1970s this type of cast making began to wane. Most of today's orthopedic casts are made of synthetic materials.

History's Famous Plaster

Artists use plaster of Paris to create sculpture, make decorative items and as a painting surface. The Greeks and Romans used plaster to create replicas of their more famous artworks. The Egyptians perfected plaster casting methods and used them to make casts of the heads of the dead in order to recreate their likenesses. The use of finely ground gypsum plaster to create decorative molding was popular during the 18th and 19th centuries. Painting in fresco is the process of painting on a thin layer of wet plaster of Paris. A well-known example of fresco work is Michelangleo's ceiling in the Sistine Chapel.

Illegal Uses of Plaster

Jack Dempsey wore plaster-soaked bandages wrapped around his hands and inside his gloves during his 1919 fight with Jess Willard, resulting in brutal injuries to Willard, including a broken jaw, broken cheekbone, broken ribs and the loss of several teeth. Plaster of Paris has also been used for the smuggling of drugs. Smugglers mix plaster of Paris with cocaine and sculpt the resulting mixture, creating objects that look like artwork.