Technique and condition
This study was painted on white wove paper with a typical glue size. There are a number of colour trials at the edges, quite thickly painted. It was possible to remove tiny samples the size of a pin-point from these, for organic analysis by Fourier transform infrared microscopy, a technique which creates a ‘fingerprint’ spectrum which can be compared to known materials. This confirmed that the paint medium is a typical gum water, and indicated the presence of the glue size on the paper.
Thin washes of pale blue and yellow were freely applied to very wet paper, until the image evolved and took form without any prior drawing. Brown earth pigments applied as equally diluted washes created the vegetation, in combination with the Prussian blue already used for the sky, and possibly with Indian yellow as well. This traditional pigment would soon be supplanted entirely in Turner’s palette by chrome yellow, which looks similar in its palest shade, but is much less prone to fading. Only the palest shade had been produced by this date, and Turner had already used it in oil in 1814, the year of its invention, in Dido and Aeneas (Tate N00494). There are several mulberry coloured patches of colour at the left hand edge, and this colour has also been used in the landscape. This one is a madder, recognisable in ultraviolet light as was the Indian yellow. The unusual bluish shade of the madder is a result of the unusual laking process used to fix or mordant the dye during pigment manufacture: iron could be detected here. Turner used several madder lake pigments with unusual mordants, and they were all found in his studio after his death. Several faded readily: it is fortunate that this study has not been exposed to much light in the nineteenth century, during which other Turner watercolours faded considerably. The even whiteness of the paper, which shows no evidence of light damage, indicates the good condition of this image.
The identification of iron in the mordant of the mulberry madder was in fact confirmed by placing a tiny sample it in the sample chamber of a scanning electron microscope, under an X-ray beam. This beam interacts with the elements that make up each pigment: pure madder is a dye and no elements would be found unless it were fixed with a mordant. The presence of madder was confirmed by Fourier transform infrared microscopy as described above, through comparison to known materials such as Turner’s studio pigments, which had also been analysed by other methods to identify their dye components.
- Yorkshire, North(770)
- River Swale(32)