Shade, in cross-hatching

A pen cannot make gray. Every mark it leaves is full black or no mark at all, and the house portrait is shaded anyway, under the eaves, inside the porch, down the wall that turns from the sun. The trick that does it is older than the printing press: draw lines close enough together and the eye supplies the gray. Cross-hatching is the grammar of that trick, and on a house it has its own rules.

One direction first

The first layer of shade is a field of parallel strokes in one direction, and the first decision is which direction. A good hand runs the first hatching along the form it shades: down a wall, across a soffit, around a column, so the strokes describe the surface while they darken it. Shade drawn against the form looks like a grid taped to the house; shade drawn with it looks like evening.

Spacing does the grading. Lines far apart give a light wash of shade for the side of the house away from the sun; lines nearly touching give the deep dark under the porch. The pen never varies its black, only its crowdedness.

Crossing for the deep places

Where the first field is not dark enough, a second is laid across it at an angle, and where that is not enough a third crosses both. Each layer multiplies the density, and the angles matter: crossings too close to parallel moiré into a shimmer, crossings too square turn to graph paper. The classic habit is to cross at roughly thirty and sixty degrees, which keeps the dark woven instead of checkered.

The deep places on a house are few and they should stay few. Under the eaves, under the porch roof, inside a recessed door, behind the balustrade: those are the notes the whole drawing keys itself against. If the deep shade spreads to the walls, the house goes dingy; kept in its pockets, it gives the light somewhere to come from.

What the shade is doing besides dark

Hatching does more than make dark. It tells the material: long even strokes for clapboard, short interrupted strokes for brick, free clustered strokes for foliage. A skilled sheet can be read like a map key, each texture announcing its surface without a word. It also tells the weather: the direction and weight of the shadows say which hour and which season the portrait is keeping.

The order of the darks

A portrait is shaded from the deepest note outward, and the order matters more than the density. The pocket under the eaves goes first, then the porch shadow, then the recessed door, and only then the broad light shade on the turned wall. Working dark to light keeps the extremes anchored: if the deepest pocket is set early, every lighter tone can be keyed against it, and the sheet arrives at its range without the muddy middle that comes from shading everything at once and hoping the darks survive.

The errors that show

Two mistakes mark the apprentice sheet. The first is outline shade, hatching that stops in a clean rectangle, which reads as a sticker pasted on the wall. Shade fades out by opening the spacing, not by drawing a border. The second is shade without a source, darkness scattered where no eave or tree explains it. Every shadow on the sheet is cast by something, and the viewer's eye goes looking for what cast it.

The sheet, filed

Cross-hatching is slow arithmetic disguised as weather: thousands of small decisions about spacing and angle adding up to a porch you can walk into. The last sheet on this board adds the layer that sits on top of all of it, the wash of watercolor over the finished ink.