I`ve painted the leaf with the following colours: Daniel Smith Hansa yellow medium and Schminke`s Ruby red, cobalt blue tone and cerulean blue tone. Hansa yellow medium is a cool yellow, the veins in this leaf appear cool although not as cool as Hansa yellow medium but its always easier to make an yellow warmer than to make it cooler. I`ve chosen Cobalt blue tone mainly because a warm blue is needed to make a good violet (for the flower) but it also makes for nice, subdued highlights on the leaf. It has a fine, powdery texture which works well here because this is not exactly a smooth leaf. I work mostly wet in wet except for the final layers. I usually put a lot of water and wait for it to sink into the paper, then start working so that the paper stays damp for a longer time. Thoroughly dry between layers, otherwise the colors from the previous layers will mix into the ones you are applying now, creating mud.
The first layer is the yellow, leaving the white of the paper for the highlight areas.
A very light blue-grey mix (tending toward blue) of cobalt blue tone-ruby red-hansa yellow medium on the highlight areas.
A yellow-green mix (tendin towards yellow) of hansa yellow medium-cerulean blue tone:
With the blue-grey mix, I started to just roughly block in the vein structure. In the beginning, when you are learning, it is actually good if you copy the structure as you see it,this exercise is helpful for learning to distinguish subtle changes in color and value. Success in building forms rests almost entirely on this. Later, ofcourse you can improvise on your own.
Here, I`ve strengthened the yellow-green mix whereever necessary, the bluish areas are lighter in comparison:
The finer veins are worked in with a darker value on a damp wash:
In the previous layers, I had wet the leaf area leaving the veins dry, here except for the central vein, I wet the entire area, so that the veins don`t look that prominent:
Sometimes I had divided the leaf up in segments to paint smaller areas, but mostly I worked on the leaf as a whole. Its easier for me to see the shadows this way. The upper part of the leaf is in cast shadow (marked CS on the photo), thrown by the leaves above it. The lower part is brighter and more yellow. The right part has an important form shadow (FS) on it, this shows how the leaf is turning in on itself, just below that is a highlight. Also on the upper right of the leaf is a highlight , caused by the reflected light from the white flower above.