Sunflowers and yellow paint

Here is the 2017 sunflower painting. I can certainly understand Van Gogh's fascination with sunflowers- somehow they are always a bit different and always interesting. Plus there is the challenge with working with yellow. Yellow pigment tends to be on the weak side - no mater what the medium it is in. I often under-paint with white so the yellow can then show to its best advantage. Today's paints are permanent but Van Gogh had trouble with his yellows because they changed with time and became more green- thus making a challenge for restorers. The question being - not only what to use - but what shade was he actually aiming at?  It is also a challenge to work shadows with yellows and not have them turn muddy, I like acrylics as the shadows can be done with glazes and it keeps the colours fresher. No vase in this one but there is in my sunflower painting in Mila's online gallery at www.va-fair.com  Van Gogh signed his name on the vase- so, as a tribute to him, I signed my  name on the vase too.  There are actually several different yellow paints in this painting- not only Cadmium Yellow Light, Medium and Dark, but also some Azo Yellow and a few more! Tjen there is Naples Yellow in with some blues and Sap Green to make the greens. Colour is fun!