Cross-Hatching That Follows the Form
How to build shadow with cross-hatching that follows the form, instead of a flat net of lines laid over the object.
Cross-hatching builds tone from lines that cross. Done well, the lines describe a surface that turns. Done as a reflex, they lay a grey net over a shape that could have been anything. The difference is the direction of the first layer. It should agree with the form, not with the angle you find easiest to repeat.
A first layer with a job
Decide the direction the surface travels. Around an arm, the lines curve with the cylinder. Down a flat wall, they can stay straight. Across a plane that faces the light, they may be so far apart that the paper does most of the work. The first layer is the drawing. The later layers only darken it.
If every first line is a diagonal at the same slant, you will get tone and no form. That diagonal is a comfort, because the wrist likes it. Change the paper's angle if you must, so the comfortable wrist direction happens to be the form's direction. Charcoal, Graphite or Ink for a Drawing changes the look of the line. It does not change the need for a direction.
Crossing without making cloth
A second layer can cross the first at a modest angle. A full right angle, repeated everywhere, starts to look like fabric or like a fence. Use the cross where the form turns away from the light and needs to be darker. Leave the lit side as a single open layer, or as bare paper.
Three layers are usually enough. After that the gaps clog, the line direction disappears, and you have made a grey the long way round. If you need a darker dark, you may be better with a softer pencil or a slower ink line than with a fourth scribble. Pencil Grades from H to B, in Plain Terms explains the grade. Hatching will not turn an H into a night sky without damaging the page.
Value still comes first
Hatching is a texture put on top of a value plan. Squint at the subject and block the large light and the large dark before you decorate them. Value First: Why a Grey Study Saves the Painting applies to a pen drawing as much as to a painting. A beautifully hatched shadow in the wrong shape is still the wrong shape.
Keep the darkest hatching for the smallest area, the place that turns right away from the light or tucks under an overlap. If the whole object is equally worked, nothing turns. The eye needs a passage of open paper in order to believe the dense passage.
A controlled exercise
Draw a simple cylinder and a simple box from life, a mug and a book. Hatch the mug with lines that wrap. Hatch the book's side plane with straights. Stop when each form is clear from arm's length. Then look for the patch where you reverted to the favourite diagonal. Redraw that patch.
In ink, plan the lit edge by not drawing it to death. You cannot lift a black net. In pencil, resist smudging the hatch into a graphite fog unless a small smudge is a deliberate transition. The line was the point.
Frequently asked questions
Must hatching always curve? No. Flat planes want straight runs. Curves want a line that agrees with the curve. The rule is agreement, not a policy of wobble.
Can I hatch in colour? Yes. Coloured strokes that follow the form mix optically and describe the surface. Strokes that ignore the form make a tartan. Keep the values readable when the hue is removed.
Why does my hatching look scratchy? The lines are probably different weights and different lengths, added in a hurry. One patient layer, evenly spaced, will look calmer than three scratchy ones. Slow the first pass.