Flora by Francesco Melzi from the state hermitage museum: Examination of the painting technique and materials

Abstract

The conservation of Francesco Melzi's Flora from the collection of the State Hermitage Museum permitted an in-depth physical–chemical study of the materials. A combined study of paint cross-sections using polarized light microscopy (PLM) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) allowed a detailed identification of the original and later restoration materials. In particular, it is likely that the original ground was chalk. Investigations of the pigment composition showed that Melzi used lead white, natural earths, red lake, vermilion and lead–tin yellow type I. Lapis lazuli was the only blue pigment, being detected in the blue drapery of Flora and in green leaves of the fern in the upper left corner of the painting, where it was used in a mixture with lead white and lead-tin yellow type I. An analysis of the sample stratigraphy of the Flora face in the shadow suggested the artist employed the sfumato technique. Binding media and other organic compounds were studied by means of thermally assisted hydrolysis and methylation-gas chromatography/mass spectrometry (THM-Py-GC/MS). It was discovered that the artist probably used poppyseed oil for the main paint layers, but egg was found in the outermost very thin white layer of Flora's clothing. The original and restoration varnishes contain a mixture of different resins and drying oil. The materials which Russian restorer Fyodor Tabuntsov used to make the transfer ground during his transposition of the painting from panel to canvas were lead white and walnut oil. It was revealed that the initial design on Flora's attire was different from the present one: a red geometric pattern was later changed to a yellow floral motif.