Colourless Powdered Glass as a Drier for Red Lakes: On the Influence of Composition and Particle Size.

Colourless glass particles are found in oil painting layers from the fifteenth-seventeenth centuries. Several historical sources mention the use of finely ground glass powder as a solid drier. In order to assess the siccative effect of glass particles added to paint, this research focused on red lake reconstructions and followed their natural drying using Fourier transform infrared (FTIR) analysis. Three glasses with different sodium-potassium and manganese contents were studied. Significant differences in drying rates were observed in each of the samples, indicating a relationship between both the composition – either enriched with or without manganese – and the size of the glass particles added as siccatives. This FTIR approach highlights several complex mechanisms involved in the drying effect of glass powders mixed in paint layers. [ABSTRACT FROM AUTHOR]