Painting the bridge with watercolors
Once the walls are done and dry I paint the bridge with Burnt Sienna and a little Permanent Alizarin Crimson. When painting the bridge I leave an arched pale line at the bottom of the bridge and a straight unpainted line along the top.
Painting the shadows
Before I paint in the people and railings I first paint the shadow shapes on the distant wall. Here is use a weak mix of French Ultramarine and Permanent Alizarin Crimson. Lean the mixture slightly to the blue not the red and use plenty of water to make is quite transparent. Put the shadow shape on very quickly and don’t fiddle or you will muddy up the underlying surface.
Remember to put the shadow color on the distant wall you can see under the bridge – for some reason I have often forgotten this and then had to mix the shadow color again when doing it later.
Use some of this same shadow mixture on the narrow section of the right hand building that faces towards you.
When the shadow shape is fully dry on the distant wall you can finish this stage by painting the people and railings on the bridge. I also painted the distant water reflections, but this could be done later.