Proceedings e report - Firenze University Press

RESSURREIÇÃO DE CRISTO – PANEL FROM THE XVI CENTURY, MUSEU DE ARTE SACRA DA SÉ DE ÉVORA
2.2. Dating of the painting
The boards of oak were prepared and marked to see the rings (Fig. 10). Then the rings were measured
with a manual magnifying glass with a scale inside (Fig. 11). With the obtained values, graphs are
made on paper. The various graphs are compared to see if the boards are from the same tree (Fig. 12).
The values are also processed by a computer program (Fig. 13) to match with a master chronology of
the same geographic origin. The oak of the Portuguese panels generally came from the Baltic region,
so we can date them, matching with the chronologies of this region, using the TsapX program (Fig.
14). The obtained value of the latest ring is an exact year. But to date the panel we must add the value
of the sapwood rings (9-36, median 15) and a storage time (2 to 10 years). So the value we add is a
statistical figure.
In this painting “Ressurreição de Cristo”, made of six boards, we measured four, the other two where
not in good condition. As we can see (Tab. 1), 1551 is the more recent and an exact year. Adding the
necessary parameters (sapwood 15 years and storage time 2 years) to this value we obtain the probable
year 1568, after which the painting was made.
Fig. 1 – “Ressurreição de Cristo”
after treatment.
Fig. 4 – Blistering on the pictorial
layer.
Fig. 7 – Damages by woodboring
anobiid beetles.
Fig. 2 – “Ressurreição de Cristo”
before treatment.
Fig. 5 – Wet rot with cuboidal
cracking.
Fig. 8 – Barb - accumulation of the
ground layer due to the original
frame.
272
Fig. 3 – “Ressurreição de Cristo” –
Detail from the inferior left corner,
burned by candles.
Fig. 6 – Fungus on the surface.
Fig. 9 – The masticage, as well the
retouching, was partial.