Oil Lamp - Production Methods

Production Methods

Before the invention of the wheel in the Middle Bronze Age, lamps were made by hand. An early form of the potter’s wheel was invented and introduced in the Middle Bronze Age and used to manufacture lamps until around the 3rd century BCE. The use of molds was first developed in Greece and Egypt during the 3rd century BCE. In Roman times, stone, clay, or plaster molds were utilized on a large scale across the Roman Empire until around the 8th century CE.

To make a lamp, two moulds are needed: one for the upper part and one for the lower part. Some pairs of moulds have knobs and corresponding holes to fit the two molds together. In order to create the mold, an archetype or patrix is first made. Plaster or clay is then formed around the patrix, which dries and hardens into a mould. Clay moulds are removed from the patrix before they are fully dried. They are then kiln fired, thus they may deviate or shrink from their original form. Clay moulds need more labour than plaster ones. However, clay moulds are more durable. Plaster moulds are dried completely and then removed from the patrix. Plaster thus makes an accurate replica, but it has the disadvantage of leaving some surface granular artifacts. Due to the perishable nature of plaster, it has proven difficult to find remains of ancient plaster moulds. Several clay moulds, however, have been recovered. By studying the surfaces of surviving lamps it seems that plaster was preferred to clay.