Portrait of N. N. Stähelin von Nördlingen with six children

The portrait miniature was executed on a parchment sheet. The infrared reflectogram (IRR) reveals an initial outline in a dry, black drawing material, particularly around the contours of the man’s hood and cloak, in the coat of arms (here featuring a central cross) and in the lower section.

X-ray fluorescence analysis (XRF) of the green paint on the columns (M1) detected several elements: copper (Cu), suggesting a copper-based green pigment; calcium (Ca), likely from calcium deposits left by the parchment liming process; lead (Pb), from an admixture of lead white; and iron (Fe), which may also originate from the parchment (see parchment reference measurement M8 [Ca, Fe]). The unicorn on the shield (M2) contains, as prominent elements, lead (Pb) and tin (Sn), indicating the use of lead-tin yellow. The presence of lead (Pb) may also result from the addition of lead white. Gold (Au) is attributable to the embellishment with shell gold on the animal’s body. The measurement point in the red section of the shield (M3) contains mercury (Hg), indicating vermillion as the red pigment. The presence of lead (Pb) suggests a mixture containing lead white, and perhaps also with red lead. A measurement point in the ochre-coloured leaf ornament at the bottom of the frame (M4) contains lead (Pb), presumably from lead white; mercury (Hg), which can be interpreted as vermillion; copper (Cu), likely present as a copper-based green or blue; and iron (Fe), suggesting an iron oxide or ochre. The blue background (M5) contains copper (Cu), indicating a copper-based blue pigment, presumably azurite. It also contains calcium (Ca) and iron (Fe)—which may originate from the parchment (see M8)—as well as lead (Pb), which suggests the presence of lead white. The blue columns in the frame (M6) contain calcium (Ca) and iron (Fe), probably from the parchment (M8), alongside copper (Cu), suggesting a copper-based blue. They also contain lead (Pb), pointing to the use of lead white. The measurement point on the borderline (M7) contains gold (Au) as a characteristic element. It also shows copper (Cu) and lead (Pb) – indicating lead white or red lead (?) – and mercury, indicating vermillion.

[Georg Josef Dietz, drawing on results from infrared reflectography and analytical evaluations by Gunnar Heydenreich and Sarah Critchley, as well as a joint study with Mailena Mallach, Luise Maul and Dominika Ropers (née Wojciechowska), March 2026]

X-ray fluorescence (XRF) (Thermo Scientific - Niton XL3t GOLDD+)

The following elements were detected using XRF and in conjunction with their optical characteristics the following fillers, drawing media and colourants could be identified:

M1 Green (border): Cu, Ca, Pb, Fe

Cu: copper-based blue/green (?); Ca: chalk/gypsum (?); Pb: lead white; Fe: iron oxide (?)

M2 Yellow (coat of arms): Pb, Ca, Sn, Fe, Hg, Cu, Au

Pb: lead white; Pb/Sn: lead-tin yellow; Ca: chalk/gypsum (?); Fe: iron oxide (?)

M3 Red (coat of arms): Hg, Ca, Pb, (Cu), (Fe)

Hg: vermillion; Ca: chalk/gypsum (?); Pb: lead white/red lead (?)

M4 Ochre yellow (border): Ca, Pb, Hg, Cu, Fe

Ca: chalk/gypsum (?); Pb: lead white; Hg: vermillion; Cu: copper-based blue / green (?); Fe: iron oxide (?)

M5 Blue (background): Cu, Ca, Fe, Pb

Cu: copper-based blue (azurite); Ca: chalk/gypsum (?); Fe: iron oxide (?); Pb: lead white

M6 Light blue (border): Ca, Cu, Fe, Pb

Ca: chalk/gypsum (?); Cu: copper-based blue (?); Fe: iron oxide (?); Pb: lead white

M7 Gold (border): Ca, Fe, Au, Cu, Pb, Hg

Ca: chalk/gypsum (?); Fe: iron oxide (?); Au: gold; Pb: lead white/red lead (?); Hg: vermillion

M8 Paper: Ca, Fe

Ca: chalk/gypsum (?); Fe: iron oxide (?)

[Gunnar Heydenreich, Sarah Critchley, unpublished analysis report, 25.07.2025]