Hair in paintings looks realistic when the artist pays attention to light and shadows.
When creating a portrait, hair is one of the most challenging things to paint. Painting hair that looks realistic is quite difficult. Improper technique can cause hair to appear fake by painting strands too far apart, painting the hair as one solid color -- which causes the hair to appear detached from the subject's head -- or painting highlights that appear muted and dirty. To achieve realistic hair, you must pay attention to detail, and utilize shadows as well as color variation and blending.
Step-by-Step
To create realistic hair in a painting, first create an outline for the hair. Think about the subject's silhouette when creating this outline. Once you have an outline, refine the shape, adding finer details such as frizz and stray hairs. Depending on the light source in the room, the subject's hair will have lighter and darker areas. Define these areas using a balance of light and dark colors. Deepen the darker areas, creating shadows and contrast. As a final step, add highlights to the hair, which will also provide contrast to make the hair seem more realistic.
Details
Attention to detail is key to painting realistic hair. For this reason, the first time you paint hair it is easiest to paint from a photograph so you can carefully study the subject's hair. Pay attention to the way your subject's hair falls, where it sticks out and how it frames the face. Observe how the subject's hair catches the light. The way the hair catches the light will depend on the light source, whether it is natural or artificial light and the location of the light, whether it is coming from overhead, behind or off to the side. Take time to notice the line of your subject's hair, where it parts and the how the bangs fall. These details will create a more realistic look when you incorporate them into your painting.
Light and Dark
Note that the hair is not a separate entity, but part of the subject's face. Depending on the location of the light source, the hair will cast shadows over the face. Incorporate these shadows into your painting. Without the inclusion of these shadows, the subject's hair will appear as if it is detached from the face. Use the light source to guide you in creating darker and lighter areas in the hair, no matter how subtle. Darker areas will represent shadows, and light areas will represent areas of the hair that are being hit directly by the light source.
Colors
When painting hair, use a mixture of shades to create a more realistic look. Hair is never one color or shade. No matter the subject's hair color, there will be a mixture of hues. Never use a generic yellow, brown, red or black to create your subject's hair color. Each strand and section should vary in color. Never use plain white to express highlights, as this will appear too bright and contribute to an unrealistic look. If you need to darken your subject's hair, don't use black, as the finished product will come out murky or muddy. Instead, use a mixture of complementary hues.
Blending
Blending is a painting technique that will contribute to hair looking more realistic. Be careful not to create harsh transitions between colors, tones or light and dark areas in the painting. Use blending to bring out the finer details in your subject's hair. Remember that darker strands sit beneath, and loose strands which are exposed to more light will appear lighter. Use blending to make sure that the transition between the subject's skin and hairline appears soft and natural.
