ToF‐SIMS study of gilding technique in the fresco Vela della Castità by Giotto's school

A Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) study on the fresco Vela della Castità by Giotto's school, located in Assisi's San Francesco Lower Basilica, reveals the chemical composition of its gilding technique. The analysis identified azelaic, palmitic, and stearic acids, confirming the use of an oil-resin binder between plaster and tin leaf, as well as colophony resin as an adhesive. This non-invasive method complements findings from other techniques like SEM-EDX and FTIR, providing a deeper understanding of medieval gilding practices on frescoes.

Biocca, P., Santopadre, P., Sidoti, G., Sotgiu, G., de Notaristefani, F., & Tortora, L. (2016). ToF‐SIMS study of gilding technique in the fresco Vela della Castità by Giotto’s school. Surface and Interface Analysis, 48(7), 404–408. Portico. https://doi.org/10.1002/sia.5956