One - Start with the centre
Define the outlines of the stamens and pistil with a very fine brush. Capture the light on each one of them.
Apply pigment to a dry surface, on the shadow side, then immediately soften the edge of the paint with a dampened water brush.
Define the other edge, almost with an outline, then soften this edge to get a nice tonal gradation.
Keep adding further layers, but complete the centre when you do the final layer. The shadows in between each stamen are very important to capture the shape well.
Two – Base colour
Yellow colours can be quite tricky to capture properly. The choice of base colour is the key to painting vivid yellows. Purple is the opposite colour of yellow, so when they are applied skilfully on top of each other, the colour will turn into grey, which makes the perfect shadow colour. Apply this purple as a base, but only where the shadow areas are. An important point here is to keep the white of the paper for the light areas of the subject. You might like to add a few layers of purple until you capture the form of the flower, but it is good to stay with the middle tones.
I used ultramarine violet directly for this flower. You can change the colour of the purple to obtain a good colour match, depending on your subject. You must always test this colour under a chosen yellow patch.
Three – Yellow on top
Apply a yellow colour on top of the base colour. Make sure the previous layer is completely dry. Dampen the paper before you apply the yellow, and focus on the light and shade.
A pale cadmium yellow is a good starting colour for this flower. Always start with a diluted mix of colours.
Use Winsor yellow for the lighter areas.
Step Four – Capture the volume
It is very important to see the light and shade on the entire flower, as well as within the details, such as each petal. Change the yellow mix depending on the light and shadow. Apply further layers on darker areas, using more diluted pigments for the light areas. Create tonal and colour contrast to capture its volume.
Colours to mix – cadmium yellow and permanent rose. Such dark colours must be applied carefully. Use them only for the darkest of shadows and the fine marks of the upper petals.
Step Five – Sharpen the image
Keep adding further yellow layers on top. You may dampen the surface before you apply any pigment, and you may need to use denser pigments on a dry surface. This will depend on the areas you are painting. If many layers have already been applied and the paper is saturated with water and pigment, perhaps a direct application of the paint, without using any water for the base, will be better. Mark the edges of each petal and capture a very clear image by applying shadow colours carefully. Deepen the deepest shadows and sharpen the stamens and pistils with a very fine brush and dry pigments.
Keep applying denser Winsor yellow pigment for the light areas.
Add cadmium yellow for a better colour match. Cadmium yellow can be a very opaque colour, so use carefully and apply only to some areas, especially on the shadow side.