Values are the degrees of lights and darks in a drawing or painting. A value sketch is used to observe a subject without much regard for structural or proportional accuracy. Here you focus on the lights and darks of your subject. One way to visually separate the structural lines from the values is to squint at your subject. This blurs the structural lines and makes the lights and darks more noticeable. For a finished drawing that employs values, it’s a good idea to do a structural sketch first to make sure the elements of your subject are in the right places.
Use Layers of Shading for Value Sketches
Begin a value sketch by first locating the areas of highlights, which will be left white. Then lightly shade the areas of overall values. The next step is to add more layers of shading for the middle values. Finally, add the darkest shading.
