The portrait seems to be done in the pencil using the <u>cross-hatched technique. </u>
<u>It is the variation of the hatching technique which uses lines positioned at different angles to produce different tones, textures, and illusions of depth. </u>The lines can meet at any angle, but the simplest one is at 90°. The darker shadows and tones can be created also by the thickness of the line, the spacing between them, or adding layers.