A multi-analytical investigation of the materials and painting technique of a wall painting from the church of Copacabana de Andamarca (Bolivia).

EUGENIA TOMASINI; DIANA CASTELLANOS; BLANCA GOMEZ; DALVA FARIA; CARLOS RUA LANDA; GABRIELA SIRACUSANO; MARTA MAIER

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 128 p. 172 - 180

0026-265X

The Andean church of Our Lady of Copacabana de Andamarca in Bolivia was built in1723. Its walls are made of adobe bricks and are decorated with paintings dated from mid18th century. Before a restoration process involving the governments of Bolivia and theFederal Republic of Germany, seven microsamples were extracted from representativecolors of one of the wall paintings inside the church. The aim of our research was tocharacterize the chromatic palette and investigate the painting technique of this Andeancolonial wall painting. To approach these goals, an integrated investigation comprising*ManuscriptClick here to view linked References2Raman and FTIR-ATR spectroscopy, optical microscopy (OM), scanning electronmicroscopy with X-ray microanalysis (SEM-EDS), gas chromatography (GC), and gaschromatography mass spectrometry (GC-MS) was carried out.The results indicated the use of a mixture of two basic copper sulfatesof mineral origin,brochantite and antlerite, as the green pigment, adding relevant information to the palette ofgreen pigments in colonial art. Yellow, orange and red ochre, abundant pigments in theAndean region, were also characterized. Observation by optical microscopy of crosssectionsof the embedded microsamples and analysis of organic binders by GC and GC-MSpointed to a secco technique and the use of a mixture of egg and vegetable oil (?temperagrassa?) as the pigment binder.In conclusion, our results allowed to establish the pigment palette and offered new insightsinto the painting technique of Andean wall paintings.