Abstrakt
The investigation was carried out on Bohemian panel paintings of 14th and beginning of 15th century from collections of the National Gallery in Prague. The aim of the investigation was to explore materials used for gilding and silvering, to analyze exact elemental composition, percentage representation of gold and silver (if found together) and also to describe structure proprieties of metallic leaves.
Another intention was to explore preparative layer under metallic leaves. Cross-sections from Bohemian paintings of 14th and beginning of 15th century were used like samples for further survey.
Optical microscopy was applied to observe cross sections and proprieties of preparative layer for plating. Scanning electron microscopy with energy dispersive spectrometer was used to determine chemical composition and to observe structure and execution of metallic leaves.
Simple layers of gilding and silvering and also superposition of these layers was revealed. Special technique of zwishgold was identified and quantity relation of gold and silver was figured out.
Zwishgold is a unique technique used in 14th and beginning of 15th century and it's very rarely found in panel painting.