How does this artwork elucidate its Material analysis?
The pigment analysis of Renoir's The Umbrellas conducted by the scientists at the National Gallery in London confirmed the assumption that it was painted in two distinct stages as mentioned above. In the dress of the woman on the left two layers have been identified: the lower layer contains cobalt blue mixed with zinc yellow and red lake. This is a similar pigment mixture as used for the woman on the right and her two daughters. Both layers have been painted during the first phase in 1881. The upper layer of the dress of the woman on the right painted during the second stage in 1886 contains a mixture of ultramarine with other pigments with a distinctly less vivid grayish-blue color.
cobalt blue ultramarine National Gallery London