Lorenzo Lotto's painting materials: an integrated diagnostic approach

Abstract

This paper presents the results of a comprehensive diagnostic investigation carried out on five paintings (three wood panels and two paintings on canvas) by Lorenzo Lotto, one of the most significant artists of the Italian Renaissance in the first half of 16th century. The paintings considered belong to 1508-1522 period, corresponding to the most significant years of Lotto's evolution. A wide array of non-invasive (reflectance spectrometry and X-ray fluorescence) and micro-invasive analytical techniques (optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, micro-FTIR spectroscopy, micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry and high performance liquid chromatography coupled with photodiode array detection and mass spectrometry) were applied in order to provide a large set of significant data, limiting as much as possible the sampling. This study has proved that Lotto's painting palette was typical of Venetian practice of that period, but some significant peculiarities emerged: the use of two kinds of red lakes, the addition of calcium carbonate and colourless powdered glass, the latter frequently found in pictorial and ground layers. Moreover, the integrated investigation showed that Lotto's technique was sometimes characterized by the use of coloured priming and multi-layer sequences with complex mixtures. Chromatographic analyses allowed to identify in all specimens: azelaic, palmitic and stearic acids, generally referring to the presence of drying oils. The extension of additional non-invasive examination to about 50 paintings by the same author, spanning from 1505 to around 1556, helped to verify the evolution in the use of some pigments, such as the yellow ones, where Pb-Sb yellow was used alongside Pb-Sn yellow.

Portable X‐ray fluorescence device reveals the artistic palette of Carlo Bononi, Baroque artist from Ferrara

“…These elements are due to the use of gypsum (CaSO 4 ) as a preparation layer (Figure shows sulphur, as will be explained later) mixed or covered (priming layer) with lead white (PbCO 3 ) and earths (aluminium silicates rich in iron oxides), as the Venetian School taught. For example, the same kind of preparation was revealed by Amadori et al on the paintings of Lorenzo Lotto, one of the most important Venetian artists of the 16th century. The dark preparation, with red and yellow ochres and umber earth mixed with lead white, was also employed by Bononi in the other canvases of the nave and in “The Triumph of the Holy Name” (oil on wall) in the apse.…”

“…The first has been acquired in air at 50 kV, 700 μA, 60 s. The second has been acquired with He flux at 30 kV, 1,300 μA, 120 s oxides), as the Venetian School taught. For example, the same kind of preparation was revealed by Amadori et al [6] on the paintings of Lorenzo Lotto, one of the most important Venetian artists of the 16th century. The dark preparation, with red and yellow ochres and umber earth mixed with lead white, was also employed by Bononi in the other canvases [7] of the nave and in "The Triumph of the Holy Name" [8] (oil on wall) in the apse.…”

Dual isotope system analysis of lead white in artworks

“…This set of techniques is often used in combination because they are complementary and allow a thorough description of the materials used in the painting. 19,20 This workflow allowed for the identification of additional interferences when carrying out the 14 C and Pb isotope analysis. The presence of other carbonates, such as chalk, would interfere with the dating of the lead white pigment, and any organic pigment or carbon black interferes in dating the binder.…”

The use of ground glass in red glazes: structural 3D imaging and mechanical behaviour using optical coherence tomography and nanoindentation

“…Here the glass particles contain manganese, added by Italian glass makers from the late thirteenth century onwards to counteract the greenish tinge caused by iron impurities in the sand or pebbles used. Amadori [6] found a lead tin yellow in a glassy matrix as well as colourless glass particles in works by the Venetian painter Lorenzo Lotto (1480-1556), both materials could plausibly be connected to the local glass industry [7]. Recent research by Melo et al [8] demonstrates the presence of glass particles, probably from a locally made glass, in two altarpieces by the Portuguese painter Francisco Joao .…”