As well as the non invasive analytical methods already mentioned in this blog (Non Invasive Diagnostics For Paintings) when appropriate, and where traditional sampling can be undertaken, pigment identification through polarized light microscopy is a particularly helpful as a quick and precise way to analyse the pigments present in a painting or polychrome object. It is widely used in conservation – and can be very helpful in dating a piece, a restoration, or a repaint – by identifying the pigments present, and knowing the date certain pigments came into use.
Identifying the precise pigments also has a wide implication in active and preventive conservation; by identifying light sensitive pigments, which enables the conservator to take the appropriate action in advising light/UV screening, as well as in helping in the choice of treatment materials to ensure materials are inert and will not have any chemical reaction with particular pigments.
Last week I took part in a course in London run by International Academic Projects and taught by conservation scientist Dr Tracey Chaplin, on the identification of pigments under the microscope, using this method. Tracey is also co-author of the excellent Pigment Compendium, a dictionary and optical microscopy of historical pigments, pictured above. I am hoping I will be able to build on the grounding of this training and start to be able to introduce some analysis through microscopy into the work I carry out and can offer in my studio in Oxford, in addition to the non invasive technologies mentioned.