Cartonnage

Plaster:

Whiting plaster (sometimes referred to as gesso) is limestone powder mixed with adhesive. This type of plaster provides a smooth surface for painting or gilding and was often used for cartonnage masks and coffins. Whiting plaster was most likely used to construct this object.

 

Gilding:

Two cartonnage masks from the Roman period were found to have red bole in the gilding substrate. The presence of bole supports a water gilding type process, as bole is necessary for water gilding. Other gilded objects from the Roman period have a yellow bole on a plaster substrate, and no bole on gesso covered wooden substrates. The lack of bole suggests an oil gilding type process, as oil gilding can be applied to surfaces without bole. This object likely underwent a water gilding type process due to the presence of bole. Water gilding can be burnished, and oil gilding cannot. The scratch marks on the face and ears could be from burnishing but could also be from past vigorous cleaning. It is unclear if the gilding was burnished.

 

Pigments:

The red pigment could be a red ochre (hydrated iron oxides), or a red lead pigment. Red ochre was used from the fifth dynasty to the Roman period. A red lead pigment called minimum was found on a fragment of Early Roman period cartonnage in the Archaeological Research Collection of the School of Religion at the University of Southern California. XRF analysis of this pigment could help determine if it is a red lead.

 

Egyptian blue a synthetic pigment created by heating up silica, copper, and an alkali material together. Egyptian blue has the potential to degrade to a superficial green or to an almost black due the malachite (which contains copper) included. The blue areas of decoration on the face appear dark green. The blue on the face appears almost black, but upon closer inspection has a green tone to it. It is unclear if this is due to mixing the Egyptian blue with a dark pigment, the result of the Egyptian blue degradation process, or both. The black pigment used is likely a carbon-based pigment.

 

Green frit was often used as in earlier periods of Egypt. It is composed of copper wollastonite, and a glassy phase high in sodium, potassium, and copper chlorides. Other greens in the Roman period were Egyptian blue mixed with orpiment (a yellow pigment), green earth, and organic copper bound by protein-based glue. Because the areas of green on this object do not luminesce under conditions for identifying Egyptian blue, the inclusion of Egyptian blue is not likely. XRF analysis can provide further information on the green pigment by identifying elements in the composition. This analysis would also be beneficial for identifying the yellow used, as pararealgar and yellow ochre were used in addition to orpiment.

 

What appears to me as a purple may be a pink, considering there were no true purples used in Egyptian paintings. The pink on this object is potentially madder painted over gypsum white as this was a common pink in the Roman period. The UV examination evidence supports the pink having a madder component. Gypsum white (calcium sulphate) and whiting chalck (calcium carbonate) are two white pigments found in ancient Egypt from the fifth dynasty to the Roman period. Lead white is also a possible pigment, though it has not been found on Egyptian objects, has been on Roman objects and may have been introduced during the Roman Period.

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