NINETEENTH-CENTURY COCHINEAL LAKE PIGMENTS FROM WINSOR & NEWTON: INSIGHT INTO THEIR METHODOLOGY THROUGH RECONSTRUCTIONS

The 19th century archive database from Winsor & Newton (W&N), one of the leading artists' colourmen at that time, was thoroughly investigated in relation to their manufacturing processes for cochineal lake pigments. Two hundred and seventy-nine production records were studied: 36% pertained to carmine; 40% to crimson; and 24% to scarlet lakes. Ten main methods of synthesis were identified and evaluated. A selection of the recipes was reconstructed with as much historical accuracy as possible. The resulting pigments were characterised with micro-Fourier transform infrared spectroscopy, UV-Vis-NIR Fibre Optic Reflectance spectroscopy, and micro-spectrofluorimetry, and successfully compared with the chemical composition of historic W&N oil paint in tubes. This work revealed the commitment that W&N made to the quality and durability of their lake pigments, while the reconstructions provide reference materials for the study of the formulations used and their response to photodegradation.