The Character Portrait: Sculpting the Alien Mystic - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 97

At this stage, I want to give the flesh of the face more character. To do this, I will sketch in a pattern of
wrinkles freehand. I will use these wrinkles to follow the overall flow of the face to suggest the kinds of
expressions the character makes by defining where the skin is folding from use. Select the Standard brush
and Alpha 01 for this wrinkle pass. Sketch in lines that radiate out from the mouth as seen in Figure 2-43 .
Use the Inflate brush with a low ZIntensity setting on the spaces between the lines to pucker up the mesh
into folds of flesh.
Figure 2-43: Sketch in the wrinkles of the face with the Standard brush.