Medieval nanotechnology: Thickness determination of Zwischgold samples

• Focused study aiming at technological parameters of corroded Mediaeval Zwischgold. • Gold layer in a nanoscale thickness range of 20–50 nm, with the peak at 30 nm. • Full foil thickness (50–260 nm) obtained from EDX derived Ag/Au weight ratio. • Ultra-high-resolution SEM measurements, supported by STEM and RBS. • Scientific evidence for paleness of Zwischgold. A special gilding material called Zwischgold has been frequently observed in...