The painting is in oil paint on an oak panel measuring 410 x 330 mm (fig.1). The panel is composed of two boards placed vertically and glued together at a butt joint, which runs just to our left of the sitter’s face (fig.2). The left board is 79 mm wide, the right 251 mm. Although the front of the panel is smooth, the back has been left with saw marks; there is a rough bevel on all edges.
The ground is dark off-white in colour and is on average 90 microns thick. It is made of chalk and animal glue. It is covered over with a thin coat of semi-translucent, pale grey, oil based priming, which is approximately 10 microns thick (figs.3–4).
Infrared reflectography revealed no significant linear underdrawing in the face or figure (fig.5).
Examination through the stereomicroscope showed that the artist applied a coat of opaque grey colour (different from the priming) over the area destined for the sleeves and the chest area of the costume; it extends into the lower part of the lace collar (fig.6).
Similarly to this painting’s pair, Portrait of an Unknown Gentleman (Tate T00744), an opaque, cool grey tone was roughly applied to the face and neck. Close examination of the eyes reveals dark red delineation there; it is visible in places where the overlying, final painting has become worn (figs.7–8). The hair was laid in with thin, reddish brown paint before being built up with more substantial, opaque colours applied with descriptive brushwork (fig.9). Thin layers of warmer and darker opaque paint were laid in wet-in-wet to the flesh to create highlights and shadows, leaving the underlying grey visible here and there to form the half-shadows (fig.10).
The opaque pinkish reds of the costume were laid in wet-in-wet, with a red organic pigment applied on top for the shadows of the costume and of the pearls (fig.11). Thick lead white paint describes highlights and the lace collar (fig.12). The very limited palette consists of black, white, browns and yellows (of hair and flesh) and organic red (cochineal-based lake) and inorganic red (vermilion).1
The painting was cleaned and restored at Tate in 1972. The varnish is composed of modern, synthetic resins.