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Colourless Powdered Glass as an Additive in Fifteenth- and Sixteenth-Century European Paintings


Selection of data presented in support of the Spring article from Technical Bulletin Volume 33.

Additional information

Table 1: Fifteenth- and sixteenth-century paintings in which colourless powdered glass has been identified in paint samples, together with quantitative SEM–EDX analysis of the particles, normalised and expressed as weight % oxide (not including elements present at values lower than 0.1%). Updates since publication of the article appear in green.

SchoolDate RangeArtist, painting title, date and locationfAreas where powdered glass was found and estimated particle sizeglass typeNa2OMgOAl2O3SiO2P2O5eSO3ClK2OCaOTiO2MnOFeO
French1498-1502Master of Moulins (Jean Hey), Charlemagne, and the meeting of Saints Joachim and Anne at the Golden Gate (NG 4092), c.1500.Purple of Joachim’s cloak; in red glaze with red lake (over pale purple), 3–7 µmbwood ash1.95.42.163.33.14.5d0.96.311.10.10.80.5
French1498-1502Master of Saint Giles, The Mass of Saint Giles (NG 4681), c.1500.Red of altar cloth, in underpaint (with vermilion) and surface paint (with red lake and a little lead white), c.10 µmawood ash1.04.72.156.94.53.6d0.811.114.10.20.60.4
German1518-1522Master of Cappenberg (Jan Baegert?), Christ before Pilate (NG 2154), c.1520.Yellow mordant for gilding, with lead white, yellow earth and lead-tin yellow, c.20 µmawood ash–lime (high lime–low potash)2.63.81.758.83.10.40.74.023.30.21.00.5
German1488-1497Master of the Aachen Altarpiece, Pilate washing his hands (Walker Art Gallery, Liverpool, no. 1225), c.1490–5, wing panel belonging with NG1049 above.Red glaze on Christ’s purple cloak, with red lake (applied over blue), c. 7–10 µmasoda ash10.14.41.868.20.20.80.81.910.30.10.80.5
German1488-1497Master of the Aachen Altarpiece, The Crucifixion (NG 1049), c.1490–5.Shadow of the Magdalen’s red cloak, with red lake, 7–20 µmasoda ash10.04.32.767.00.42.2d0.82.09.30.10.60.5
German1483-1492Master of the Life of the Virgin, The Conversion of Saint Hubert: Left Hand Shutter (NG 252), c.1485–90.Brownish-yellow mordant for gold harness on horse, with lead white, lead-tin yellow, some black and earth; red pattern on Saint Hubert’s tunic, with red lake (c.3–10 µm)awood ash–lime (high lime–low potash)1.63.34.754.43.65.7d0.33.621.10.30.40.7
German1460-1475Master of the Life of the Virgin, The Presentation in the Temple (NG 706), probably 1460–75.Mordant for the gilding on the Virgin’s robe, with lead white, yellow earth and lead-tin yellow (c. 3–10 µm)asoda ash (leached)7.13.81.669.80.42.3d1.31.810.20.10.71.1
German1505-1510Master of the Saint Bartholomew Altarpiece, Saints Peter and Dorothy (NG 707), probably 1505–10.Saint Dorothy’s pink underdress, with red lake and lead white, 5–50 µmawood ash–lime (high lime–low potash)1.63.01.958.93.20.80.64.923.40.30.70.6
German1498-1507Master of the Saint Bartholomew Altarpiece, The Deposition (NG 6470), c.1500–05.Shadow of Saint John’s red cloak, with red lake, 2–10 µmawood ash–lime (high lime–low potash)0.52.24.351.13.65.3d0.65.025.70.01.20.5
German1561Nicolas de Neufchâtel, Portrait of a Young Lady (NG 184), probably 1561, Nuremberg.Brownish-grey background, with lead white and black, 5–10 µmawood ash–lime (high lime–low potash)0.82.22.251.03.70.40.59.225.70.23.50.6
German1518-1522Wolf Huber, Christ taking leave of his Mother (NG 6550), c.1520.Shadow of the red robe of the woman supporting Mary, with red lake, two types of glass, 5–50 µmasoda ash (leached?); Type I8.22.71.767.70.50.50.93.511.90.11.51.0
German1518-1522Wolf Huber, Christ taking leave of his Mother (NG 6550), c.1520.Shadow of the red robe of the woman supporting Mary, with red lake, two types of glass, 5–50 µmawood ash: Type II0.12.60.953.30.90.50.121.318.90.30.80.6
German1498-1512Workshop of Albrecht Dürer, The Virgin and Child ('The Madonna with the Iris') (NG5592), c.1500–10.Red dress and cloak of the Virgin, with red lake, 5–20 µmawood ash–lime (high lime–low potash)2.43.05.855.53.32.0d0.74.621.00.20.90.5
German1483-1492Workshop of the Master of the Life of the Virgin, The Mass of Saint Hubert: Right Hand Shutter (NG 253), c.1485–90.Red undersleeve of the figure behind Saint Hubert, with red lake, c. 10–20 µmasoda ash11.74.02.666.60.30.51.02.110.30.10.20.5
German1510-1514Workshop of the Master of the Saint Bartholomew Altarpiece, The Virgin and Child in Glory with Saints (NG 6497), c.1512.Virgin’s red dress, with red lake; yellow-brown mordant for gilding, with lead white, yellow earth and lead-tin yellow, 10–20 µmawood ash–lime (high lime–low potash)2.64.13.056.93.71.9d1.03.521.50.40.90.5
Italian1602-1606Annibale Carracci, The Dead Christ Mourned ('The Three Maries') (NG 2923), c.1604.Red of the Magdalen’s drapery, with red lake, 5–15 µmasoda ash (leached)9.02.84.4g60.70.20.20.96.713.30.20.90.6
Italian1518-1522Antonio da Vendri, The Giusti Family of Verona(?) (NG 749), probably c.1520, Verona.Translucent off white priming layer; mainly glass, with a little lead white, 20–40 µmasoda ash12.02.71.070.20.31.01.23.87.10.00.30.4
Italian1498-1507Attributed to Pietro Perugino, Christ crowned with Thorns (NG 691), c.1500–05.Pale yellow priming, with lead white and a little lead-tin yellow, c.10 µmasoda ash11.83.04.5h60.31.12.7d0.94.77.80.22.10.9
Italian1515Bacchiacca, Joseph pardons his Brothers (NG 1219), probably 1515, Florence.Pale yellow priming (a little), with lead white and lead-tin yellow, (Mn detected by XRF), c.5 µmasoda ash12.32.74.5h62.40.42.3d0.83.37.60.22.60.9
Italian1548-1572Bronzino, Portrait of Piero de' Medici (NG 1323), probably c.1550–70.Sitter’s red tunic, with red lake and a little lead white (Mn detected by XRF), 2–3 μmasoda ash (leached)6.42.710.5g60.80.84.3d0.74.66.60.11.70.7
Italian1538-1542Bronzino, The Madonna and Child with Saint John the Baptist and Saint Elizabeth (NG 5280), probably c.1540, Florence.Virgin’s red sleeve, with lead white and red lake (Mn detected by XRF), 5–7 μmbsoda ash11.52.74.8g62.30.23.4d0.05.07.20.11.20.6
Italian1517-1521Domenico Beccafumi, Marcia (NG 6369), c.1519, Siena.Pale yellow priming, with lead white and a little lead-tin yellow, 10–30 µm, one particle 80 µmbsoda ash11.62.50.966.40.34.7d1.03.58.20.10.30.5
Italian1517-1521Domenico Beccafumi, Tanaquil (NG 6368), c.1519, Siena, transferred from panel.Pale yellow priming, with lead white and a little lead-tin yellow, 10–30 µmbsoda ash (leached)5.22.80.975.90.62.1d1.22.97.50.00.40.4
Italian1523-1527Domenico Beccafumi, The Story of Papirius (NG 1430), mid 1520s, Siena.Translucent priming (glass only); red dress of woman at the centre of group below steps, mixed with red lake and azurite, 10–20 µmasoda ash12.52.54.8h62.40.71.2d0.94.87.60.21.90.6
Italian1527-1529Dosso Dossi , The Adoration of the Kings (NG 3924), probably 1527–9, Ferrara.Pink cloak of one of the kings, 5–10 µmasoda ash (leached)5.61.91.575.60.30.91.24.47.60.00.50.4
Italian1513-1518Francesco Francia, Mourning over the Dead Christ (NG 2671), probably c.1515–16, Bologna.Pale yellow priming, with lead white and a little lead-tin yellow; purple-red cloak of woman at right edge, with red lake, c.5 µmbsoda ash11.92.71.168.80.22.0d1.12.38.90.10.50.4
Italian1508-1514Francesco Francia, The Virgin and Child with Saint Anne and other Saints (NG 179), c.1510–12, Bologna, transferred from panel.Dark purple shadow in Saint Anne’s robe, with red lake, a little ultramarine and a little lead white, 10–30 µmbsoda ash9.32.72.067.00.50.90.66.39.10.11.00.6
Italian1488-1501Francesco Napoletano (?), An Angel in Green with a Vieille (NG 1661), c.1490–9, Milan.Red sleeve of angel, with red lake, 20–30 µmbsoda ash10.43.30.966.30.41.3d0.85.99.30.21.00.4
Italian1510-1518Gerolamo dai Libri, The Virgin and Child with Saint Anne (NG 748), 1510–18, VeronaPriming, with some lead white; underpaint of the cangiante drapery of the angel on the left, 10–30 µmasoda ash (leached)8.13.21.967.10.50.30.43.712.70.11.50.4
Italian1508-1514Giovanni Battista da Faenza, The Incredulity of Saint Thomas (NG 1051), c.1510–12, Faenza.Priming; mainly glass with a little lead white and lead-tin yellow, 5–30 µmbsoda ash10.53.71.265.90.32.6d1.21.911.30.10.60.7
Italian1510-1518Giovanni Battista da Faenza, The Virgin and Child in Glory (NG 282), c.1512–16, Faenza.Priming, mainly glass with a little lead white, 5–30 µmbsoda ash10.43.41.768.10.31.6d0.92.010.50.20.50.5
Italian1486-1490Giovanni Santi, The Virgin and Child (NG 751), about 1488, probably Urbino.Crimson drapery underneath the Christ Child, with red lakeasoda ash7.92.81.868.90.40.70.92.612.20.11.00.6
Italian1460-1550Imitator of Mantegna, Noli me Tangere (NG 639), perhaps 1460–1550.Pale yellow priming, with lead white and a little lead-tin yellow, 5–15 µmasoda ash14.22.83.863.80.60.70.83.26.90.12.40.8
Italian1515Jacopo Pontormo, Pharoah with his Butler and Baker (NG 6452), probably 1515, Florence.Pale yellow priming, with lead white and lead-tin yellow; brown paint of architecture (Mn detected by XRF), 5–15 µmasoda ash12.22.83.664.20.60.50.73.98.00.22.40.9
Italian1470-1479Justus of Ghent and workshop, Music (NG 756) probably 1470s, probably Urbino.Red of carpet, with red lakebsoda ash11.43.94.9g60.50.62.3d0.73.210.30.21.20.8
Italian1512-1517Lodovico Mazzolino, The Holy Family with Saint Francis (NG 82), probably c.1514–15, Ferrara.Pale yellow priming, with lead white and a little lead-tin yellowasoda ash9.03.01.169.50.40.70.72.410.50.12.30.5
Italian1486-1492Lorenzo Costa, A Concert (NG 2486), c.1488–90, Bologna.Off white priming, with a little lead white; black background, with coal black and a little verdigris; underpaint of marbled ledge, with lead white, a little red lake and brown; purple cloak of figure at the right, with red lake and a little lead white in the upper layer and with coal black, a little red lake, vermilion and lead-tin yellow in underpaint, 10–30 µmbsoda ash11.23.71.766.00.32.9d0.92.29.60.10.80.6
Italian1499Lorenzo Costa, Gianfrancesco Maineri, The Virgin and Child Enthroned between a Soldier Saint, and Saint John the Baptist (La Pala Strozzi) (NG 1119), probably 1499, probably Ferrara.Off white priming, with a little lead white; Virgin’s red dress, with red lake; grey sword, with lead white and galena (lead sulphide); grey of architecture, with lead white and bone black; Saint John’s red cloak, with red lake and azurite, 10–30 µmbsoda ash11.63.81.566.70.41.2d0.92.19.80.11.40.5
Italian1505Lorenzo Costa, High Altarpiece, Oratory of S. Pietro in Vincoli (NG 629), 1505, probably Bologna, transferred from panel.Pale yellow priming, with lead white and a little lead-tin yellow; deep red of Saint Philip’s cloak, with red lake and a little lead white and vermilion; brownish-grey architecture, with lead white, verdigris, lead-tin yellow and galena (lead sulphide), 5–20 µmbsoda ash12.53.81.766.80.30.70.92.210.00.10.50.4
Italian1507Marco Marziale, The Virgin and Child with Saints (NG 804), 1507, Venice or Cremona.Red of Virgin’s robe, with red lake and white in the underpaint, and red lake only in upper layers, 10–30 µmasoda ash (leached)9.73.21.071.50.30.30.92.110.10.00.50.3
Italian1492-1496Master of the Story of Griselda, The Story of Griselda, Part III: Reunion (NG 914), c.1494, probably Siena.Grey of horse, with lead white and black, 5–10 µmasoda ash11.22.94.5h61.50.50.30.93.811.60.01.81.0
Italian1498-1503Michelangelo, The Entombment (NG 790), c.1500–1, RomePale yellow priming, with lead white and a little lead-tin yellow, 5–20 µmasoda ash12.54.31.468.50.70.61.01.78.30.00.60.4
Italian1518-1522Ortolano, Saints Sebastian, Roch and Demetrius (NG 699), c.1520, Ferrara, transferred from original panel.Red drapery, with red lake and some vermilion, c. 5 µmasoda ash, many particles very leached11.63.64.5g65.60.41.10.72.58.00.11.60.5
Italian1505-1517Pietro Perugino, The Virgin and Child with Saints Jerome and Francis (NG 1075), probably c.1507–15.Pale yellow priming, with lead white and a little lead-tin yellow; Saint Jerome’s red robe, with red lake, 10–20 µm, two types of glassasoda ash; high Al (sand)12.42.05.4h68.00.60.21.13.25.30.11.20.6
Italian1505-1517Pietro Perugino, The Virgin and Child with Saints Jerome and Francis (NG 1075), probably c.1507–15.Pale yellow priming, with lead white and a little lead-tin yellow; Saint Jerome’s red robe, with red lake, 10–20 µm, two types of glassasoda ash; low Al (pebbles)11.43.61.162.40.17.7d1.13.28.00.10.41.1
Italian1494-1502Pietro Perugino, Three Panels from an Altarpiece, Certosa (NG 288.1–3), c.1496–1500.Pale yellow priming, with lead white and lead-tin yellow; Raphael’s red robe, with red lake, 5–10 µmasoda ash (slightly leached); priming7.12.94.0h62.21.26.3d1.13.49.10.22.01.0
Italian1494-1502Pietro Perugino, Three Panels from an Altarpiece, Certosa (NG 288.1–3), c.1496–1500.Pale yellow priming, with lead white and lead-tin yellow; Raphael’s red robe, with red lake, 5–10 µmasoda ash; red paint11.23.45.0g62.60.70.60.63.69.10.22.40.7
Italian1505-1509Raphael, Saint Catherine of Alexandria (NG 168), c.1507, Florence.Pale yellow priming, with lead white and a little lead-tin yellow; Saint Catherine’s red cloak, with red lake; yellow-brown paint of wheel, with lead white, red earth, umber and a little azurite and vermilion; brownish-green of the background landscape, with lead-tin yellow, azurite, yellow earth and a little black, 10–40 µmasoda ash11.52.84.1h64.30.60.40.03.78.80.22.40.7
Italian1505Raphael, Saint John the Baptist Preaching (NG 6480), 1505, Umbria or Florence (predella of The Ansidei Altarpiece).Pale yellow priming, with lead white and a little lead-tin yellow; grey hose of figure fourth from the left, with lead white and coal black; red of cloak of figure second from the left, with red lake and vermilion; brownish-green foreground, with lead white, lead-tin yellow and a little azurite and verdigris, two types of glass, 10–20 µmasoda ash; high Al (sand)11.53.05.5h65.60.60.51.23.17.30.21.10.6
Italian1505Raphael, Saint John the Baptist Preaching (NG 6480), 1505, Umbria or Florence (predella of The Ansidei Altarpiece).Pale yellow priming, with lead white and a little lead-tin yellow; grey hose of figure fourth from the left, with lead white and coal black; red of cloak of figure second from the left, with red lake and vermilion; brownish-green foreground, with lead white, lead-tin yellow and a little azurite and verdigris, two types of glass, 10–20 µmasoda ash; low Al (pebbles)8.73.02.267.20.83.7d0.92.69.60.21.00.5
Italian1500-1505Raphael, The Crucified Christ with the Virgin Mary, Saints and Angels (The Mond Crucifixion) (NG 3943), c.1502–3, Umbria.Pale yellow priming, with lead white and a little lead-tin yellow; Saint John’s red drapery, with red lake; golden sun ray, with orpiment and a little lead-tin yellow; brown shadow of the drapery of the angel in yellow, with black, vermilion, red earth and red lake, 10–30 µmasoda ash10.43.41.069.90.20.30.92.210.70.00.50.4
Italian1505Raphael, The Madonna and Child with Saint John the Baptist and Saint Nicholas of Bari (The Ansidei Madonna) (NG 1171), 1505, Umbria or Florence.Pale yellow priming, with lead white and a little lead-tin yellow; dark purple underside of the canopy over the throne, with red lake, a little vermilion and black; Saint John’s red drapery, with red lake; pale grey architecture, with lead white and bismuth metal powder; mordant for the gilded decoration on the throne (used alone); yellow ‘wood’ on the throne, with lead-tin yellow and a little red earth, two types of glass, 10–20 µmasoda ash; high Al (sand)11.82.45.0h63.60.51.01.23.58.10.21.61.0
Italian1505Raphael, The Madonna and Child with Saint John the Baptist and Saint Nicholas of Bari (The Ansidei Madonna) (NG 1171), 1505, Umbria or Florence.Pale yellow priming, with lead white and a little lead-tin yellow; dark purple underside of the canopy over the throne, with red lake, a little vermilion and black; Saint John’s red drapery, with red lake; pale grey architecture, with lead white and bismuth metal powder; mordant for the gilded decoration on the throne (used alone); yellow ‘wood’ on the throne, with lead-tin yellow and a little red earth, two types of glass, 10–20 µmasoda ash; low Al (pebbles)10.93.21.566.60.21.4d0.02.410.40.11.00.5
Italian1507-1512Raphael, The Madonna and Child with the Infant Baptist (The Garvagh Madonna) (NG 744), c.1509–10.Pale yellow priming, with lead white and a little lead-tin yellow; Virgin’s red dress, with red lake, 5–20 µmbsoda ash, many particles very leached13.51.95.4h63.70.51.01.03.86.00.12.21.0
Italian1504-1509Raphael, The Madonna of the Pinks (La Madonna dei Garofani) (NG 6596), c.1506–7, Florence.Pale yellow priming, with lead white and a little lead-tin yellow, 5–10 µmasoda ash11.53.20.770.70.41.00.92.28.80.00.20.4
Italian1502-1507Raphael, The Procession to Calvary (NG 2919), c.1504–5, Umbria or Florence.Pale yellow priming, with lead white and a little lead-tin yellow; pale pink underpaint of Saint John’s red drapery, with lead white and faded red lake; greenish foreground, with lead white, lead-tin yellow, yellow earth and azurite; orange-yellow tunic of the man on the brown horse, with lead-tin yellow and yellow earth, 5–15 µmasoda ash10.93.45.1h64.40.60.80.93.08.70.21.40.7
Italian1515-1521Sebastiano del Piombo, The Raising of Lazarus (NG 1), c.1517–19, Rome, transferred from original panel.Christ’s red cloak, with red lake, a little ultramarine and lead white; brownish-pink flesh of the leg of Lazarus, with lead white and earth pigments, 5–15 µma,iVery leached, probably soda ash (low P); flesh paint0.11.50.888.30.40.81.10.55.40.00.40.8
Italian1515-1521Sebastiano del Piombo, The Raising of Lazarus (NG 1), c.1517–19, Rome, transferred from original panel.Christ’s red cloak, with red lake, a little ultramarine and lead white; brownish-pink flesh of the leg of Lazarus, with lead white and earth pigments, 5–15 µma,iVery leached, probably soda ash (low P); red paint0.12.16.2g77.40.92.8d1.11.36.30.21.00.7
Italian1498-1502Vincenzo Foppa. The Adoration of the Kings (NG 729), perhaps c.1500, Lombardy.Translucent priming layer, with a little lead white, 20–30 µmawood ash0.66.12.351.04.15.5d0.413.115.60.20.90.6
Italian1498-1502Workshop of Francesco Francia, The Virgin and Child with Two Saints (NG 638), probably c.1500, Bologna.Brown window ledge, with red earth and lead white, 10–30 µmbsoda ash10.83.51.467.50.41.11.02.410.40.10.50.8
Netherlandish1498-1502After Robert Campin, The Virgin and Child in an Apse with Two Angels (NG 2608), c.1500?Pale pink tile, with lead white and fluorite, c.30 µmawood ash–lime (high lime–low potash)1.72.61.356.82.80.90.53.727.10.61.20.8
Netherlandish1463-1467Attributed to the workshop of Rogier van der Weyden, Pietà (NG 6265), c.1465.Saint Jerome’s red cloak, with red lake and vermilion, c.2–3 µma,cwood ash1.95.75.447.06.36.9d0.79.715.10.00.50.7
Netherlandish1468-1472Dirk Bouts, Christ Crowned with Thorns (NG 1083) c.1470.Christ’s red cloak, in underpaint (with vermilion) and surface paint (with red lake and a little vermilion), 2–20 µmawood ash–lime (high lime–low potash)2.63.24.657.44.01.2d0.73.920.70.31.00.4
Netherlandish1463-1467Dirk Bouts, The Virgin and Child (NG 2595), c.1465.Red pattern on cloth-of-gold hanging, with red lake and lead white, or with red lake only in darkest shadows, 5–20 µmbwood ash–lime1.53.23.954.93.61.3d0.96.621.60.21.70.6
Netherlandish1438-1442Follower of Robert Campin, The Virgin and Child before a Firescreen (NG 2609), c.1440.Red cushion, with red lake, vermilion and a little lead white, c.10 µmb,cwood ash1.34.14.753.04.64.2d1.211.714.50.10.60.4
Netherlandish1488-1502Hieronymous Bosch, Christ Mocked (The Crowning with Thorns) (NG4744), c.1490–1500.Red headdress of figure at left, with vermilion and red lead in underpaint, with red lake in uppermost red glaze, 5–10 µmawood ash–lime (high lime–low potash)2.53.72.855.63.44.5d0.94.121.20.20.60.4
Netherlandish1432-1438Jan van Eyck, The Annunciation, National Gallery of Art, Washington (inv.1937.1.39), c.1434–6Red paint, with red lake and coal black; yellow mordant for gold rays with lead white, yellow earth and a little lead-tin yellow; two types of glass, 5–20 µmb,cwood ash–lime; Type I1.04.02.457.13.01.10.17.522.00.21.10.5
Netherlandish1432-1438Jan van Eyck, The Annunciation, National Gallery of Art, Washington (inv.1937.1.39), c.1434–6Red paint, with red lake and coal black; yellow mordant for gold rays with lead white, yellow earth and a little lead-tin yellow; two types of glass, 5–20 µmb,cwood ash: Type II2.44.54.053.66.63.3d0.67.216.20.20.60.9
Netherlandish1434Jan van Eyck, The Arnolfini Portrait (NG 186), 1434.Red curtain, in underpaint (with vermilion, red lake, black and a little ultramarine) and surface paint (with red lake and a little lead white), Arnolfini's purple robe, with red lake and a little ultramarine, three types of glassj, c.5 µmawood ash with some fern ash?: Type I0.44.51.555.04.90.40.317.114.00.31.30.5
Netherlandish1434Jan van Eyck, The Arnolfini Portrait (NG 186), 1434.Red curtain, in underpaint (with vermilion, red lake, black and a little ultramarine) and surface paint (with red lake and a little lead white), Arnolfini's purple robe, with red lake and a little ultramarine, three types of glassj, c.5 µmawood ash: Type II3.26.32.949.76.01.8d0.810.116.30.10.91.6
Netherlandish1434Jan van Eyck, The Arnolfini Portrait (NG 186), 1434.Red curtain, in underpaint (with vermilion, red lake, black and a little ultramarine) and surface paint (with red lake and a little lead white), Arnolfini's purple robe, with red lake and a little ultramarine, three types of glassj, c.5 µmawood ash–lime: Type III1.73.52.753.83.24.3d0.46.322.20.10.90.8
Netherlandish1570Joachim Beuckelaer, The Four Elements: Air (NG 6587), 1570.Red cloth in the basket in the foreground, shadow, with red lake, 10–20 µmawood ash–lime0.72.73.957.42.40.80.47.621.90.31.20.7
Netherlandish1538-1542Martin van Heemskerck, The Virgin and Saint John the Evangelist (NG 6508.1), c.1540.Saint John’s red robe, in underpaint (with vermilion and red lake) and surface paint (with red lake and a little black), 20–30 µmawood ash1.94.91.756.03.40.40.611.617.70.30.80.8
Netherlandish1433-1437Rogier van der Weyden, The Magdalen Reading (NG 654), before 1438.Saint John’s red cloak, in underpaint (with vermilion) and surface paint (with red lake and a little lead white), c.5 µma,cwood ash0.74.52.354.55.24.4d0.513.912.80.20.70.4
Netherlandish1463-1467Workshop of Dirk Bouts, The Virgin and Child (NG 708), c.1465.Virgin’s red cloak, shadow, with red lake, c.5 µmawood ash2.05.73.254.64.63.9d1.19.913.50.20.70.5
Netherlandish1513-1517Workshop of Goossen van der Weyden, The Flight into Egypt (NG 1084), c.1515.Shadow of Saint Joseph’s red drapery; underpaint (with vermilion, black and white) and upper layers (with red lake and varying amounts of white and black), 5–10 µma,cwood ash–lime (high lime–low potash)1.83.46.251.44.85.6d0.94.220.30.30.70.4
Netherlandish1518-1522Workshop of Jean Bellegambe, The Virgin and Child (NG 265), c.1520.Virgin's red cloak, with red lake, mostly 2–5 µm, one particle 70 µmbwood ash–lime (high lime–low potash): Type I2.03.13.159.32.60.40.55.422.10.20.60.7
Netherlandish1538-1542Workshop of Marinus van Reymerswaele, Two Tax Gatherers (NG 944), c.1540Shadow of red robe of man at right, with red lake (lower glaze layers only, and not final blotted glaze), c.10–20 µmawood ash–lime (high lime–low potash)1.53.14.061.03.00.70.55.419.00.30.90.7
Spanish1565-1570Luis de Morales, The Virgin and Child (NG 1229), probably 1565–70.Red of Virgin’s dress, with red lake and a little lead white, 5–7 µmasoda ash, some particles leached11.53.52.367.50.52.7d1.43.55.80.10.70.6


a. Analysis carried out on carbon-coated samples under high vacuum conditions, 200 pA, 25 kV, 60s livetime.
b. Analysis carried out on uncoated samples under variable pressure conditions, 200 pA, 25 kV, 60s livetime, 50 Pa, air as the chamber gas.
c. Particles that seem to be a pure form of silica, containing only small amounts of other elements, were also detected in this sample.
d. The apparent elevated sulphur concentration in this sample is probably not reliable and likely to result either from a sulphur-containing red lake pigment or, due to overlap of the sulphur peak with that from lead, a contribution to the spectrum from lead pigments around the glass.
e. Red lake pigments, especially those based on insect dyestuffs, often contain phosphorus. This could contribute to the apparent concentration in the glass, especially where the particles are small.
f. The binding medium of many of these paintings has been analysed by Gas Chromatography–Mass Spectrometry and identified as a drying oil. These analyses have generally been published in past issues of the National Gallery Technical Bulletin.
g. In this sample the glass particles are very small and are embedded in a matrix of red lake, with a substrate containing alumina. The interaction volume of the electron beam is likely to be larger than the glass particle and the apparent aluminium concentration too high.
h. The quantitative results quoted are from a particle in the priming layer, which does not contain red lake, or from a large particle in red lake paint; the high reported Al content is therefore reliable.
i. A dispersion of a paint sample allowed individual glass particles to be seen in transmitted light under the microscope. They could be seen to have angular edges and showed conchoidal fracture, confirming that they were glass, despite the rather low alkali content seen by EDX analysis, which is a result of severe leaching. See the Appendix in J. Dunkerton and H. Howard, ‘Sebastiano del Piombo’s Raising of Lazarus: A History of Change’, National Gallery Technical Bulletin, 30, 2009, pp. 26–51.
j. Details updated after publication, 2012.

:

SchoolArtist, painting title, date and locationfAreas where powdered glass was found and estimated particle sizeglass typeNa2OMgOAl2O3SiO2P2O5eSO3ClK2OCaOTiO2MnOFeO
FrenchMaster of Moulins (Jean Hey), Charlemagne, and the meeting of Saints Joachim and Anne at the Golden Gate (NG 4092), c.1500.Purple of Joachim’s cloak; in red glaze with red lake (over pale purple), 3–7 µmbwood ash1.95.42.163.33.14.5d0.96.311.10.10.80.5
FrenchMaster of Saint Giles, The Mass of Saint Giles (NG 4681), c.1500.Red of altar cloth, in underpaint (with vermilion) and surface paint (with red lake and a little lead white), c.10 µmawood ash1.04.72.156.94.53.6d0.811.114.10.20.60.4
GermanMaster of Cappenberg (Jan Baegert?), Christ before Pilate (NG 2154), c.1520.Yellow mordant for gilding, with lead white, yellow earth and lead-tin yellow, c.20 µmawood ash–lime (high lime–low potash)2.63.81.758.83.10.40.74.023.30.21.00.5
GermanMaster of the Aachen Altarpiece, Pilate washing his hands (Walker Art Gallery, Liverpool, no. 1225), c.1490–5, wing panel belonging with NG1049 above.Red glaze on Christ’s purple cloak, with red lake (applied over blue), c. 7–10 µmasoda ash10.14.41.868.20.20.80.81.910.30.10.80.5
GermanMaster of the Aachen Altarpiece, The Crucifixion (NG 1049), c.1490–5.Shadow of the Magdalen’s red cloak, with red lake, 7–20 µmasoda ash10.04.32.767.00.42.2d0.82.09.30.10.60.5
GermanMaster of the Life of the Virgin, The Conversion of Saint Hubert: Left Hand Shutter (NG 252), c.1485–90.Brownish-yellow mordant for gold harness on horse, with lead white, lead-tin yellow, some black and earth; red pattern on Saint Hubert’s tunic, with red lake (c.3–10 µm)awood ash–lime (high lime–low potash)1.63.34.754.43.65.7d0.33.621.10.30.40.7
GermanMaster of the Life of the Virgin, The Presentation in the Temple (NG 706), probably 1460–75.Mordant for the gilding on the Virgin’s robe, with lead white, yellow earth and lead-tin yellow (c. 3–10 µm)asoda ash (leached)7.13.81.669.80.42.3d1.31.810.20.10.71.1
GermanMaster of the Saint Bartholomew Altarpiece, Saints Peter and Dorothy (NG 707), probably 1505–10.Saint Dorothy’s pink underdress, with red lake and lead white, 5–50 µmawood ash–lime (high lime–low potash)1.63.01.958.93.20.80.64.923.40.30.70.6
GermanMaster of the Saint Bartholomew Altarpiece, The Deposition (NG 6470), c.1500–05.Shadow of Saint John’s red cloak, with red lake, 2–10 µmawood ash–lime (high lime–low potash)0.52.24.351.13.65.3d0.65.025.70.01.20.5
GermanNicolas de Neufchâtel, Portrait of a Young Lady (NG 184), probably 1561, Nuremberg.Brownish-grey background, with lead white and black, 5–10 µmawood ash–lime (high lime–low potash)0.82.22.251.03.70.40.59.225.70.23.50.6
GermanWolf Huber, Christ taking leave of his Mother (NG 6550), c.1520.Shadow of the red robe of the woman supporting Mary, with red lake, two types of glass, 5–50 µmasoda ash (leached?); Type I8.22.71.767.70.50.50.93.511.90.11.51.0
GermanWolf Huber, Christ taking leave of his Mother (NG 6550), c.1520.Shadow of the red robe of the woman supporting Mary, with red lake, two types of glass, 5–50 µmawood ash: Type II0.12.60.953.30.90.50.121.318.90.30.80.6
GermanWorkshop of Albrecht Dürer, The Virgin and Child ('The Madonna with the Iris') (NG5592), c.1500–10.Red dress and cloak of the Virgin, with red lake, 5–20 µmawood ash–lime (high lime–low potash)2.43.05.855.53.32.0d0.74.621.00.20.90.5
GermanWorkshop of the Master of the Life of the Virgin, The Mass of Saint Hubert: Right Hand Shutter (NG 253), c.1485–90.Red undersleeve of the figure behind Saint Hubert, with red lake, c. 10–20 µmasoda ash11.74.02.666.60.30.51.02.110.30.10.20.5
GermanWorkshop of the Master of the Saint Bartholomew Altarpiece, The Virgin and Child in Glory with Saints (NG 6497), c.1512.Virgin’s red dress, with red lake; yellow-brown mordant for gilding, with lead white, yellow earth and lead-tin yellow, 10–20 µmawood ash–lime (high lime–low potash)2.64.13.056.93.71.9d1.03.521.50.40.90.5
ItalianAnnibale Carracci, The Dead Christ Mourned ('The Three Maries') (NG 2923), c.1604.Red of the Magdalen’s drapery, with red lake, 5–15 µmasoda ash (leached)9.02.84.4g60.70.20.20.96.713.30.20.90.6
ItalianAntonio da Vendri, The Giusti Family of Verona(?) (NG 749), probably c.1520, Verona.Translucent off white priming layer; mainly glass, with a little lead white, 20–40 µmasoda ash12.02.71.070.20.31.01.23.87.10.00.30.4
ItalianAttributed to Pietro Perugino, Christ crowned with Thorns (NG 691), c.1500–05.Pale yellow priming, with lead white and a little lead-tin yellow, c.10 µmasoda ash11.83.04.5h60.31.12.7d0.94.77.80.22.10.9
ItalianBacchiacca, Joseph pardons his Brothers (NG 1219), probably 1515, Florence.Pale yellow priming (a little), with lead white and lead-tin yellow, (Mn detected by XRF), c.5 µmasoda ash12.32.74.5h62.40.42.3d0.83.37.60.22.60.9
ItalianBronzino, Portrait of Piero de' Medici (NG 1323), probably c.1550–70.Sitter’s red tunic, with red lake and a little lead white (Mn detected by XRF), 2–3 μmasoda ash (leached)6.42.710.5g60.80.84.3d0.74.66.60.11.70.7
ItalianBronzino, The Madonna and Child with Saint John the Baptist and Saint Elizabeth (NG 5280), probably c.1540, Florence.Virgin’s red sleeve, with lead white and red lake (Mn detected by XRF), 5–7 μmbsoda ash11.52.74.8g62.30.23.4d0.05.07.20.11.20.6
ItalianDomenico Beccafumi, Marcia (NG 6369), c.1519, Siena.Pale yellow priming, with lead white and a little lead-tin yellow, 10–30 µm, one particle 80 µmbsoda ash11.62.50.966.40.34.7d1.03.58.20.10.30.5
ItalianDomenico Beccafumi, Tanaquil (NG 6368), c.1519, Siena, transferred from panel.Pale yellow priming, with lead white and a little lead-tin yellow, 10–30 µmbsoda ash (leached)5.22.80.975.90.62.1d1.22.97.50.00.40.4
ItalianDomenico Beccafumi, The Story of Papirius (NG 1430), mid 1520s, Siena.Translucent priming (glass only); red dress of woman at the centre of group below steps, mixed with red lake and azurite, 10–20 µmasoda ash12.52.54.8h62.40.71.2d0.94.87.60.21.90.6
ItalianDosso Dossi , The Adoration of the Kings (NG 3924), probably 1527–9, Ferrara.Pink cloak of one of the kings, 5–10 µmasoda ash (leached)5.61.91.575.60.30.91.24.47.60.00.50.4
ItalianFrancesco Francia, Mourning over the Dead Christ (NG 2671), probably c.1515–16, Bologna.Pale yellow priming, with lead white and a little lead-tin yellow; purple-red cloak of woman at right edge, with red lake, c.5 µmbsoda ash11.92.71.168.80.22.0d1.12.38.90.10.50.4
ItalianFrancesco Francia, The Virgin and Child with Saint Anne and other Saints (NG 179), c.1510–12, Bologna, transferred from panel.Dark purple shadow in Saint Anne’s robe, with red lake, a little ultramarine and a little lead white, 10–30 µmbsoda ash9.32.72.067.00.50.90.66.39.10.11.00.6
ItalianFrancesco Napoletano (?), An Angel in Green with a Vieille (NG 1661), c.1490–9, Milan.Red sleeve of angel, with red lake, 20–30 µmbsoda ash10.43.30.966.30.41.3d0.85.99.30.21.00.4
ItalianGerolamo dai Libri, The Virgin and Child with Saint Anne (NG 748), 1510–18, VeronaPriming, with some lead white; underpaint of the cangiante drapery of the angel on the left, 10–30 µmasoda ash (leached)8.13.21.967.10.50.30.43.712.70.11.50.4
ItalianGiovanni Battista da Faenza, The Incredulity of Saint Thomas (NG 1051), c.1510–12, Faenza.Priming; mainly glass with a little lead white and lead-tin yellow, 5–30 µmbsoda ash10.53.71.265.90.32.6d1.21.911.30.10.60.7
ItalianGiovanni Battista da Faenza, The Virgin and Child in Glory (NG 282), c.1512–16, Faenza.Priming, mainly glass with a little lead white, 5–30 µmbsoda ash10.43.41.768.10.31.6d0.92.010.50.20.50.5
ItalianGiovanni Santi, The Virgin and Child (NG 751), about 1488, probably Urbino.Crimson drapery underneath the Christ Child, with red lakeasoda ash7.92.81.868.90.40.70.92.612.20.11.00.6
ItalianImitator of Mantegna, Noli me Tangere (NG 639), perhaps 1460–1550.Pale yellow priming, with lead white and a little lead-tin yellow, 5–15 µmasoda ash14.22.83.863.80.60.70.83.26.90.12.40.8
ItalianJacopo Pontormo, Pharoah with his Butler and Baker (NG 6452), probably 1515, Florence.Pale yellow priming, with lead white and lead-tin yellow; brown paint of architecture (Mn detected by XRF), 5–15 µmasoda ash12.22.83.664.20.60.50.73.98.00.22.40.9
ItalianJustus of Ghent and workshop, Music (NG 756) probably 1470s, probably Urbino.Red of carpet, with red lakebsoda ash11.43.94.9g60.50.62.3d0.73.210.30.21.20.8
ItalianLodovico Mazzolino, The Holy Family with Saint Francis (NG 82), probably c.1514–15, Ferrara.Pale yellow priming, with lead white and a little lead-tin yellowasoda ash9.03.01.169.50.40.70.72.410.50.12.30.5
ItalianLorenzo Costa, A Concert (NG 2486), c.1488–90, Bologna.Off white priming, with a little lead white; black background, with coal black and a little verdigris; underpaint of marbled ledge, with lead white, a little red lake and brown; purple cloak of figure at the right, with red lake and a little lead white in the upper layer and with coal black, a little red lake, vermilion and lead-tin yellow in underpaint, 10–30 µmbsoda ash11.23.71.766.00.32.9d0.92.29.60.10.80.6
ItalianLorenzo Costa, Gianfrancesco Maineri, The Virgin and Child Enthroned between a Soldier Saint, and Saint John the Baptist (La Pala Strozzi) (NG 1119), probably 1499, probably Ferrara.Off white priming, with a little lead white; Virgin’s red dress, with red lake; grey sword, with lead white and galena (lead sulphide); grey of architecture, with lead white and bone black; Saint John’s red cloak, with red lake and azurite, 10–30 µmbsoda ash11.63.81.566.70.41.2d0.92.19.80.11.40.5
ItalianLorenzo Costa, High Altarpiece, Oratory of S. Pietro in Vincoli (NG 629), 1505, probably Bologna, transferred from panel.Pale yellow priming, with lead white and a little lead-tin yellow; deep red of Saint Philip’s cloak, with red lake and a little lead white and vermilion; brownish-grey architecture, with lead white, verdigris, lead-tin yellow and galena (lead sulphide), 5–20 µmbsoda ash12.53.81.766.80.30.70.92.210.00.10.50.4
ItalianMarco Marziale, The Virgin and Child with Saints (NG 804), 1507, Venice or Cremona.Red of Virgin’s robe, with red lake and white in the underpaint, and red lake only in upper layers, 10–30 µmasoda ash (leached)9.73.21.071.50.30.30.92.110.10.00.50.3
ItalianMaster of the Story of Griselda, The Story of Griselda, Part III: Reunion (NG 914), c.1494, probably Siena.Grey of horse, with lead white and black, 5–10 µmasoda ash11.22.94.5h61.50.50.30.93.811.60.01.81.0
ItalianMichelangelo, The Entombment (NG 790), c.1500–1, RomePale yellow priming, with lead white and a little lead-tin yellow, 5–20 µmasoda ash12.54.31.468.50.70.61.01.78.30.00.60.4
ItalianOrtolano, Saints Sebastian, Roch and Demetrius (NG 699), c.1520, Ferrara, transferred from original panel.Red drapery, with red lake and some vermilion, c. 5 µmasoda ash, many particles very leached11.63.64.5g65.60.41.10.72.58.00.11.60.5
ItalianPietro Perugino, The Virgin and Child with Saints Jerome and Francis (NG 1075), probably c.1507–15.Pale yellow priming, with lead white and a little lead-tin yellow; Saint Jerome’s red robe, with red lake, 10–20 µm, two types of glassasoda ash; high Al (sand)12.42.05.4h68.00.60.21.13.25.30.11.20.6
ItalianPietro Perugino, The Virgin and Child with Saints Jerome and Francis (NG 1075), probably c.1507–15.Pale yellow priming, with lead white and a little lead-tin yellow; Saint Jerome’s red robe, with red lake, 10–20 µm, two types of glassasoda ash; low Al (pebbles)11.43.61.162.40.17.7d1.13.28.00.10.41.1
ItalianPietro Perugino, Three Panels from an Altarpiece, Certosa (NG 288.1–3), c.1496–1500.Pale yellow priming, with lead white and lead-tin yellow; Raphael’s red robe, with red lake, 5–10 µmasoda ash (slightly leached); priming7.12.94.0h62.21.26.3d1.13.49.10.22.01.0
ItalianPietro Perugino, Three Panels from an Altarpiece, Certosa (NG 288.1–3), c.1496–1500.Pale yellow priming, with lead white and lead-tin yellow; Raphael’s red robe, with red lake, 5–10 µmasoda ash; red paint11.23.45.0g62.60.70.60.63.69.10.22.40.7
ItalianRaphael, Saint Catherine of Alexandria (NG 168), c.1507, Florence.Pale yellow priming, with lead white and a little lead-tin yellow; Saint Catherine’s red cloak, with red lake; yellow-brown paint of wheel, with lead white, red earth, umber and a little azurite and vermilion; brownish-green of the background landscape, with lead-tin yellow, azurite, yellow earth and a little black, 10–40 µmasoda ash11.52.84.1h64.30.60.40.03.78.80.22.40.7
ItalianRaphael, Saint John the Baptist Preaching (NG 6480), 1505, Umbria or Florence (predella of The Ansidei Altarpiece).Pale yellow priming, with lead white and a little lead-tin yellow; grey hose of figure fourth from the left, with lead white and coal black; red of cloak of figure second from the left, with red lake and vermilion; brownish-green foreground, with lead white, lead-tin yellow and a little azurite and verdigris, two types of glass, 10–20 µmasoda ash; high Al (sand)11.53.05.5h65.60.60.51.23.17.30.21.10.6
ItalianRaphael, Saint John the Baptist Preaching (NG 6480), 1505, Umbria or Florence (predella of The Ansidei Altarpiece).Pale yellow priming, with lead white and a little lead-tin yellow; grey hose of figure fourth from the left, with lead white and coal black; red of cloak of figure second from the left, with red lake and vermilion; brownish-green foreground, with lead white, lead-tin yellow and a little azurite and verdigris, two types of glass, 10–20 µmasoda ash; low Al (pebbles)8.73.02.267.20.83.7d0.92.69.60.21.00.5
ItalianRaphael, The Crucified Christ with the Virgin Mary, Saints and Angels (The Mond Crucifixion) (NG 3943), c.1502–3, Umbria.Pale yellow priming, with lead white and a little lead-tin yellow; Saint John’s red drapery, with red lake; golden sun ray, with orpiment and a little lead-tin yellow; brown shadow of the drapery of the angel in yellow, with black, vermilion, red earth and red lake, 10–30 µmasoda ash10.43.41.069.90.20.30.92.210.70.00.50.4
ItalianRaphael, The Madonna and Child with Saint John the Baptist and Saint Nicholas of Bari (The Ansidei Madonna) (NG 1171), 1505, Umbria or Florence.Pale yellow priming, with lead white and a little lead-tin yellow; dark purple underside of the canopy over the throne, with red lake, a little vermilion and black; Saint John’s red drapery, with red lake; pale grey architecture, with lead white and bismuth metal powder; mordant for the gilded decoration on the throne (used alone); yellow ‘wood’ on the throne, with lead-tin yellow and a little red earth, two types of glass, 10–20 µmasoda ash; high Al (sand)11.82.45.0h63.60.51.01.23.58.10.21.61.0
ItalianRaphael, The Madonna and Child with Saint John the Baptist and Saint Nicholas of Bari (The Ansidei Madonna) (NG 1171), 1505, Umbria or Florence.Pale yellow priming, with lead white and a little lead-tin yellow; dark purple underside of the canopy over the throne, with red lake, a little vermilion and black; Saint John’s red drapery, with red lake; pale grey architecture, with lead white and bismuth metal powder; mordant for the gilded decoration on the throne (used alone); yellow ‘wood’ on the throne, with lead-tin yellow and a little red earth, two types of glass, 10–20 µmasoda ash; low Al (pebbles)10.93.21.566.60.21.4d0.02.410.40.11.00.5
ItalianRaphael, The Madonna and Child with the Infant Baptist (The Garvagh Madonna) (NG 744), c.1509–10.Pale yellow priming, with lead white and a little lead-tin yellow; Virgin’s red dress, with red lake, 5–20 µmbsoda ash, many particles very leached13.51.95.4h63.70.51.01.03.86.00.12.21.0
ItalianRaphael, The Madonna of the Pinks (La Madonna dei Garofani) (NG 6596), c.1506–7, Florence.Pale yellow priming, with lead white and a little lead-tin yellow, 5–10 µmasoda ash11.53.20.770.70.41.00.92.28.80.00.20.4
ItalianRaphael, The Procession to Calvary (NG 2919), c.1504–5, Umbria or Florence.Pale yellow priming, with lead white and a little lead-tin yellow; pale pink underpaint of Saint John’s red drapery, with lead white and faded red lake; greenish foreground, with lead white, lead-tin yellow, yellow earth and azurite; orange-yellow tunic of the man on the brown horse, with lead-tin yellow and yellow earth, 5–15 µmasoda ash10.93.45.1h64.40.60.80.93.08.70.21.40.7
ItalianSebastiano del Piombo, The Raising of Lazarus (NG 1), c.1517–19, Rome, transferred from original panel.Christ’s red cloak, with red lake, a little ultramarine and lead white; brownish-pink flesh of the leg of Lazarus, with lead white and earth pigments, 5–15 µma,iVery leached, probably soda ash (low P); flesh paint0.11.50.888.30.40.81.10.55.40.00.40.8
ItalianSebastiano del Piombo, The Raising of Lazarus (NG 1), c.1517–19, Rome, transferred from original panel.Christ’s red cloak, with red lake, a little ultramarine and lead white; brownish-pink flesh of the leg of Lazarus, with lead white and earth pigments, 5–15 µma,iVery leached, probably soda ash (low P); red paint0.12.16.2g77.40.92.8d1.11.36.30.21.00.7
ItalianVincenzo Foppa. The Adoration of the Kings (NG 729), perhaps c.1500, Lombardy.Translucent priming layer, with a little lead white, 20–30 µmawood ash0.66.12.351.04.15.5d0.413.115.60.20.90.6
ItalianWorkshop of Francesco Francia, The Virgin and Child with Two Saints (NG 638), probably c.1500, Bologna.Brown window ledge, with red earth and lead white, 10–30 µmbsoda ash10.83.51.467.50.41.11.02.410.40.10.50.8
NetherlandishAfter Robert Campin, The Virgin and Child in an Apse with Two Angels (NG 2608), c.1500?Pale pink tile, with lead white and fluorite, c.30 µmawood ash–lime (high lime–low potash)1.72.61.356.82.80.90.53.727.10.61.20.8
NetherlandishAttributed to the workshop of Rogier van der Weyden, Pietà (NG 6265), c.1465.Saint Jerome’s red cloak, with red lake and vermilion, c.2–3 µma,cwood ash1.95.75.447.06.36.9d0.79.715.10.00.50.7
NetherlandishDirk Bouts, Christ Crowned with Thorns (NG 1083) c.1470.Christ’s red cloak, in underpaint (with vermilion) and surface paint (with red lake and a little vermilion), 2–20 µmawood ash–lime (high lime–low potash)2.63.24.657.44.01.2d0.73.920.70.31.00.4
NetherlandishDirk Bouts, The Virgin and Child (NG 2595), c.1465.Red pattern on cloth-of-gold hanging, with red lake and lead white, or with red lake only in darkest shadows, 5–20 µmbwood ash–lime1.53.23.954.93.61.3d0.96.621.60.21.70.6
NetherlandishFollower of Robert Campin, The Virgin and Child before a Firescreen (NG 2609), c.1440.Red cushion, with red lake, vermilion and a little lead white, c.10 µmb,cwood ash1.34.14.753.04.64.2d1.211.714.50.10.60.4
NetherlandishHieronymous Bosch, Christ Mocked (The Crowning with Thorns) (NG4744), c.1490–1500.Red headdress of figure at left, with vermilion and red lead in underpaint, with red lake in uppermost red glaze, 5–10 µmawood ash–lime (high lime–low potash)2.53.72.855.63.44.5d0.94.121.20.20.60.4
NetherlandishJan van Eyck, The Annunciation, National Gallery of Art, Washington (inv.1937.1.39), c.1434–6Red paint, with red lake and coal black; yellow mordant for gold rays with lead white, yellow earth and a little lead-tin yellow; two types of glass, 5–20 µmb,cwood ash–lime; Type I1.04.02.457.13.01.10.17.522.00.21.10.5
NetherlandishJan van Eyck, The Annunciation, National Gallery of Art, Washington (inv.1937.1.39), c.1434–6Red paint, with red lake and coal black; yellow mordant for gold rays with lead white, yellow earth and a little lead-tin yellow; two types of glass, 5–20 µmb,cwood ash: Type II2.44.54.053.66.63.3d0.67.216.20.20.60.9
NetherlandishJan van Eyck, The Arnolfini Portrait (NG 186), 1434.Red curtain, in underpaint (with vermilion, red lake, black and a little ultramarine) and surface paint (with red lake and a little lead white), Arnolfini's purple robe, with red lake and a little ultramarine, three types of glassj, c.5 µmawood ash with some fern ash?: Type I0.44.51.555.04.90.40.317.114.00.31.30.5
NetherlandishJan van Eyck, The Arnolfini Portrait (NG 186), 1434.Red curtain, in underpaint (with vermilion, red lake, black and a little ultramarine) and surface paint (with red lake and a little lead white), Arnolfini's purple robe, with red lake and a little ultramarine, three types of glassj, c.5 µmawood ash: Type II3.26.32.949.76.01.8d0.810.116.30.10.91.6
NetherlandishJan van Eyck, The Arnolfini Portrait (NG 186), 1434.Red curtain, in underpaint (with vermilion, red lake, black and a little ultramarine) and surface paint (with red lake and a little lead white), Arnolfini's purple robe, with red lake and a little ultramarine, three types of glassj, c.5 µmawood ash–lime: Type III1.73.52.753.83.24.3d0.46.322.20.10.90.8
NetherlandishJoachim Beuckelaer, The Four Elements: Air (NG 6587), 1570.Red cloth in the basket in the foreground, shadow, with red lake, 10–20 µmawood ash–lime0.72.73.957.42.40.80.47.621.90.31.20.7
NetherlandishMartin van Heemskerck, The Virgin and Saint John the Evangelist (NG 6508.1), c.1540.Saint John’s red robe, in underpaint (with vermilion and red lake) and surface paint (with red lake and a little black), 20–30 µmawood ash1.94.91.756.03.40.40.611.617.70.30.80.8
NetherlandishRogier van der Weyden, The Magdalen Reading (NG 654), before 1438.Saint John’s red cloak, in underpaint (with vermilion) and surface paint (with red lake and a little lead white), c.5 µma,cwood ash0.74.52.354.55.24.4d0.513.912.80.20.70.4
NetherlandishWorkshop of Dirk Bouts, The Virgin and Child (NG 708), c.1465.Virgin’s red cloak, shadow, with red lake, c.5 µmawood ash2.05.73.254.64.63.9d1.19.913.50.20.70.5
NetherlandishWorkshop of Goossen van der Weyden, The Flight into Egypt (NG 1084), c.1515.Shadow of Saint Joseph’s red drapery; underpaint (with vermilion, black and white) and upper layers (with red lake and varying amounts of white and black), 5–10 µma,cwood ash–lime (high lime–low potash)1.83.46.251.44.85.6d0.94.220.30.30.70.4
NetherlandishWorkshop of Jean Bellegambe, The Virgin and Child (NG 265), c.1520.Virgin's red cloak, with red lake, mostly 2–5 µm, one particle 70 µmbwood ash–lime (high lime–low potash): Type I2.03.13.159.32.60.40.55.422.10.20.60.7
NetherlandishWorkshop of Marinus van Reymerswaele, Two Tax Gatherers (NG 944), c.1540Shadow of red robe of man at right, with red lake (lower glaze layers only, and not final blotted glaze), c.10–20 µmawood ash–lime (high lime–low potash)1.53.14.061.03.00.70.55.419.00.30.90.7
SpanishLuis de Morales, The Virgin and Child (NG 1229), probably 1565–70.Red of Virgin’s dress, with red lake and a little lead white, 5–7 µmasoda ash, some particles leached11.53.52.367.50.52.7d1.43.55.80.10.70.6


a. Analysis carried out on carbon-coated samples under high vacuum conditions, 200 pA, 25 kV, 60s livetime.
b. Analysis carried out on uncoated samples under variable pressure conditions, 200 pA, 25 kV, 60s livetime, 50 Pa, air as the chamber gas.
c. Particles that seem to be a pure form of silica, containing only small amounts of other elements, were also detected in this sample.
d. The apparent elevated sulphur concentration in this sample is probably not reliable and likely to result either from a sulphur-containing red lake pigment or, due to overlap of the sulphur peak with that from lead, a contribution to the spectrum from lead pigments around the glass.
e. Red lake pigments, especially those based on insect dyestuffs, often contain phosphorus. This could contribute to the apparent concentration in the glass, especially where the particles are small.
f. The binding medium of many of these paintings has been analysed by Gas Chromatography–Mass Spectrometry and identified as a drying oil. These analyses have generally been published in past issues of the National Gallery Technical Bulletin.
g. In this sample the glass particles are very small and are embedded in a matrix of red lake, with a substrate containing alumina. The interaction volume of the electron beam is likely to be larger than the glass particle and the apparent aluminium concentration too high.
h. The quantitative results quoted are from a particle in the priming layer, which does not contain red lake, or from a large particle in red lake paint; the high reported Al content is therefore reliable.
i. A dispersion of a paint sample allowed individual glass particles to be seen in transmitted light under the microscope. They could be seen to have angular edges and showed conchoidal fracture, confirming that they were glass, despite the rather low alkali content seen by EDX analysis, which is a result of severe leaching. See the Appendix in J. Dunkerton and H. Howard, ‘Sebastiano del Piombo’s Raising of Lazarus: A History of Change’, National Gallery Technical Bulletin, 30, 2009, pp. 26–51.
j. Details updated after publication, 2012.