The importance of tonal values cannot be understated. The application of light and shadow to a painting is just about the most important thing to get right when it comes to creating an appealing image. Even the most beautifully composed paintings can fall flat if their values are incorrect, so before thinking about adding colour it’s a good idea to get your greyscale base image looking tip-top first.
Many of the world’s greatest digital artists begin their creative process by painting in black and white, leaving it until later to apply colour washes by way of different layer modes. But this technique is by no means exclusive to the digital realm, or even present-day artists for that matter.
Painting in monotone and applying colour later on is an approach that dates way back to the 13th Century. The verdaccio and grisaille techniques were used to lay down a monotone underpainting to which colour would be applied. While grisaille uses grey tones made from mixing black and white, whereas verdaccio appears cooler due to the additional green pigment. The tint achieved when using verdaccio is widely believed to produce more accurate skin tones when the subsequent glazes are applied.
For this image I loosely followed the same process used for a traditional oil painting to create a digital underpainting before adding colour, using verdaccio under my skin tones and grisaille under the rest of the image.
Light source Using a single light source is a good way to exaggerate facial features. This is also a convenient way to paint as it eliminates many of the complexities that arise when having to paint a subject affected by multiple sources.
Rim light A subtler secondary light source can help define the edges of figures and objects. The soft light coming from the windows on the right provide an opportunity to add some rim lighting and define the rat’s silhouette more clearly.
Vague background elements For a scene with a figure as the main focus, it is not always necessary to work lots of detail into the surroundings. Working in silhouette with a slight colour wash gives the vague impression of plants in front of the window.
Eyes Traditional portraits usually show the subject looking directly at the viewer, with the eyes and eyebrows being the facial features most responsible for conveying the subject’s emotion. It is therefore worth taking the time to make the eyes bold.
Boost values When nearing the completion of an image, a good final step is to give the values a boost. Adding a little more strength to the light and shadow can bring a painting to life in the later stages. This is easily done with an Overlay layer.