I am currently reading Anthony Bailey’s biography of JMW Turner, Standing in the Sun, (2013 paperback edition). So having just posted about Smalt Blue, I was very interested to read the following lines from Henry Syer Trimmer’s account of Turner’s studio, after Turner’s death, ” … and cobalt to be sure there was, but also several bottles of ultramarine of various depths and smalts of various intensities, of which I think he made great use.” Trimmer goes on to report, “I was told by his housekeeper [Hannah Danby] that ultramarine was employed by him sparingly, and that Smalt and cobalt were his usual blues.” ( pps 87-88).
In this case Trimmer is referring to Turner’s oil paints, rather than his watercolour paints. I am trying to find out whether Turner used the same pigments in his watercolours. It seems quite likely, as it is a matter of selecting the relevant binder for your pigment and ensuring that the particles are ground down to the correct specification that are the key. I need to do some more research!
To give you some idea of the colours Trimmer is referring to, above, I have swatched out the three blues referred to, Ultramarine, Smalt Blue and Cobalt Blue, in watercolours. In addition I have also included three other blues, Indanthrone Blue (AKA Delft Blue), Mayan Blue Genuine and Pthalo Blue (green shade) for comparison.
Most interesting of all these pigments to me is Mayan Blue which, according to Wikipedia is “a composite of organic and inorganic constituents, primarily indigo dyes derived from the leaves of añil (Indigofera suffruticosa) plants combined with palygorskite, a natural clay which, mysteriously, is not known to exist in abundant deposits in Mesoamerica.”
Indanthrone Blue, PB 60, also goes by more than one name, including Delft Blue and sometimes indigo blue. I would be wary of using the latter common name as the indigo blues I have looked up on line are made from a varying range of pigments. White Nights Indigo (Nevskya Palitra) is a blend of PBk 7, PB 15 and PV 3; Windsor and Newton Indigo is a blend of PBk 6, PV 19 and PB 15.
When choosing a watercolour to add to your palette the general advice is to select a paint made from a single pigment. This will generally give better results when mixing colours. If you are selecting a multi-pigment paint you are more likely to mix a muddy colour. This is because some of the pigments may work well in the mix and others may not thereby cancelling each other out and making mud.