THE USE OF NATURAL ORGANIC COLORING MATERIALS ON BYZANTINE AND POST-BYZANTINE ICONS

• Sister Daniilia, A. Tsakalof, K. Andrikopoulos, I. Chryssoulakis ("Ormylia" Art Diagnosis Center, Sacred Convent of the Annunciation, 630 71 Ormylia, Chalkidiki, Greece)
• J. Wouters, I. Vanden Berghe (Royal Institute for Cultural Heritage, Laboratory for Materials and Techniques, Jubelpark 1, B-1000 Brussels, Belgium )

Introduction: It can be stated that up to the present time mainly the use of inorganic pigments in Byzantine icon painting has been investigated, although not so systematically. Lately there can be also noted the growing interest in the investigation of the Byzantine painters' use of the organic pigments. In spite of the fact that the employment of such materials in paintings has been known from the ancient times, there are almost no data verifying their use in Byzantine icons.

In the present study the multilateral approach to the question of organic pigments use in Byzantine paintings has been started aiming at

Materials and methods: The icons that have been investigated in the present study originate from the Mount Athos and different parts of Chalkidiki and are dated from the middle of 14th up to the end of 16th centuries. The organic coloring materials were identified on the basis of HPLC -PDA, ìRAMAN and ìFTIR data.

Results: In the investigated icons the employment of a blue organic dye (indigo or woad) and red-purple lakes derived from Mexican cochineal (Dactylopius coccus), brazilwood (Caesalpinia spp.) and kermes (kermes vermilio) has been discovered. Sometimes, several of these sources were found to have been mixed in the organic pigment. Mexican cochineal was detected only in 16th centuries dated icons.

The pure indigo or its mixture with lead white was used in the underlay of garments. The lights were usually made from the same pigment and increasing the amount of lead white, while in other cases indigo was substituted by azurite mixed also with lead white. Almost pure brazilwood was applied on the white gesso ground and the gradations of the lights were achieved by the small additions of lead white.

In post-Byzantine icons the Mother of God's mantle was made by the use of inorganic pigments and the artists, rather than choosing a pale violet hue for a final aesthetic touch, covered the surface with glaze of red lake. On the saints' garments usually red lake was mixed with lead white to achieve pale pink shades. In some icons lake was applied on an underlay comprising inorganic pigments, leading to increasing the transparency and the degree of saturation.

Conclusions: The use of organic chromatic materials in post Byzantine icons of 16th century has been verified. The main types of organic pigments used and also the techniques of their application were identified.

The attestation of the use of organic pigments even in the painting of an icon dated at the 14th century suggests a further thorough study in order to define the time period of introduction of the natural organic pigments to the Byzantine iconography as well as to follow the expansion of their use with the evolution of the techniques and styles.