The colours of a 16th century panel painting, from the church of Pavia (Mora, Portugal), attributed to Francisco João

Abstract

The main altar of the church of Pavia (Mora, South of Portugal) shows a 16th century panel painting depicting The Conversion of Saint Paul attributed to Francisco João, a local painter, born in Évora, active in that region between 1563 and 1595. With the aim of identifying the materials responsible for the colours exhibited by the painting and characterizing its technique, the panel was examined in situ with the naked eye and with the help of a magnifying lens. Nine paint samples were collected for analysis by optical microscopy, scanning electron microscopy - energy dispersive X-ray spectrometry (SEM-EDX), Fourier transformed infrared spectroscopy (FTIR) and high-performance thin layer chromatography (HPTLC). On top of a ground layer made of gypsum and animal glue, the painting was done with lead white, lead-tin yellow, ochre, minium, red ochre, vermillion, azurite, verdigris or copper resinate, carbon black and a non identified red lake. In most cases, the samples show a succession of two or three layers of paint over the ground. Generally, this structure results from the modelling work of the painter and not from overlapping motives. In each layer, the colours were usually created by mixtures of a coloured pigment with white. In two cases, the pigments were used pure. Only the red areas show mixtures of a larger number of materials.

Keywords

• Painting
• 16th century
• Colour
• Pigments
• Pigments' mixtures
• Modelling technique