THE CORONATION OF THE VIRGIN ALTARPIECE

SCIENTIFIC ANALYSES 

• Dendrochronology:

- Baltic oak.

- Dated: terminus post quem of 1521.

- Several fragments of the altarpiece come from the same trees (five identified).

• 64 Helicoidal multi-slice scan

Several fragments and joints in the relief of the Last Supper

•  Chemical analyses of the materials

Preparation: calcium carbonate mixed with animal glue, applied in several coats and variable thicknesses, depending on the area to be decorated.

Coat of waterproof protein primer beneath the flesh tones, black protein undercoat for blue azurite, oily orange-coloured undercoat with minium used in continuous brocades and very diluted reddish bole under the burnished gilt leaves.

Good quality gilt (1.4 - 2.6% silver)

Mordant: linseed oil and pigments (20-35 µm)

Pigments: white lead, minium, black charcoal, verdigris, yellow tin-lead, clays, vermillion and red kermes and madder lake glazes probably obtained from dyed cloth.