Japanese gold leaf artists worked on nanoscale
|Pair of two-leaf screens Deer. Ogata Kōrin (1658-1716). Glue tempera and gold |
leaf on paper, 163.5 x 178.8cm (each screen). Early 18th century, Edo period.
[Credit: Seikado Bunko Art Museum, Tokyo]
Pessanha's team examined six screens that are currently either part of a museum collection or in a private collection in Portugal. Four screens belong to the Momoyama period, and two others were decorated during the early Edo period. The researchers used various X-ray fluorescence spectroscopy techniques to test the thickness and characteristics of the gold layers. The method is completely non-invasive, no samples needed to be taken, and therefore the artwork was not damaged in any way. Also, the apparatus needed to perform these tests is portable and can be done outside of a laboratory.
The gilding was evaluated by taking the attenuation or weakening of the different characteristic lines of gold leaf layers into account. The methodology was tested to be suitable for high grade gold alloys with a maximum of 5 percent influence of silver, which is considered negligible.
The two screens from the early Edo period were initially thought to be of the same age. However, Pessanha's team found that gold leaf on a screen kept at Museu Oriente in Lisbon was thinner, hence was made more recently. This is in line with the continued development of the gold beating techniques carried out in an effort to obtain ever thinner gold leaf.
"This simple comparison allowed establishing a timeline between the manufacture of two pieces attributed to the same period, proving that X-ray fluorescence techniques can be an important asset in the dating of artworks," says Pessanha.
The results are published in Springer's journal Applied Physics A: Material Science and Processing.
Source: Springer Science [July 02, 2014]