03 — Grammar
A line can describe a boundary, a movement, or something that is not there yet. Learn the difference by seeing each mark on its own.
What each mark means, when it helps, and when to leave it out. Hover over a drawing to isolate the marks being explained, then move away to see the whole construction.
Use these meanings in your own brief, or explore the shared linework tokens.
Mark 01
Identity, name, and tools assemble into one record. Primary outlines hold the loose fragments and finished form together; quieter face details and construction lines support them.
Keep supporting marks subordinate. Giving every stroke equal weight makes the construction compete with the subject.
The fragments and completed record read first.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 02
Two availability intervals share one time window. The translucent fill marks their intersection; the rest of each interval stays transparent.
Use a highlight for a named selection, intersection, or result. Paint it once, and omit it when the outline or hatching already explains the same relationship.
Only the shared portions of the two intervals are shaded.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 03
Hatching singles out one bounded region. Here it identifies a visible iris blade while the aperture remains clear. Its direction and spacing stay consistent across that region.
Omit hatching when no region needs distinguishing. It is not a lighting effect or a material label.
One blade is selected; its boundaries and the central opening stay clear.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 04
A grid makes a shared construction module visible. This letter’s stem, counter, and bowl radii all follow the same 32-unit field.
Omit a background grid when local guides already explain the relationship. Geometric subject matter alone is not a reason to add one.
The grid reveals one module across the stem, counter, and bowl.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 05
The curved dashed line and its solid open arrowhead show a rigid part turning from its current position to the proposed one. The nearby “Quarter turn” text is a callout, not part of the arrow.
Use an arrow only when a change or direction matters; alignment and equal size need different marks.
On hover, only the dashed shaft and solid arrowhead remain.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 06
A callout connects a short label to the feature it names. Here the bent solid leader anchors “Quarter turn” to the curved movement path. The leader and label form one annotation.
Omit labels that add no meaning. Keep the leader subordinate and end it on the named feature; use movement arrows for direction and dimensions for measurements.
On hover, only the leader and “Quarter turn” label remain.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 07
A whole task separates into two assigned scopes. Each projection connects the same width witness before and after separation, so the parts retain a visible relationship to the whole.
Omit guides that cannot name both corresponding features. Nearby endpoints are not enough: the alignment must be exact.
Four quiet guides preserve the same two allocations.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 08
Dimensions reveal the proportions that construct a form. Here a concentric bend keeps a constant offset, while its width and radius use the same unit.
Omit measurements that do not explain the construction. Every witness and radius leader must reach the feature it measures.
One unit system connects the width, offset, and actual circular radius.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 09
Centerlines and a pitch circle reveal how repeated features share one center. Six curved slots follow the same circle at equal angular intervals.
Omit axes and loci that do not explain symmetry, rotation, or placement. A dashed guide must pass through the geometry it claims to organize.
On hover, the center mark, radial axes, and pitch circle remain; the slots and callout disappear.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.
Mark 10
The dashed C-shaped boundary represents a channel behind the plate’s visible front face. The channel exists, but this view cannot see it directly. Only that hidden boundary remains on hover.
Hidden means present but concealed; absent means missing; proposed means a possible future form. Label the intended state. The solid line pointing to “Hidden rear channel” is a callout leader, a separate annotation that disappears on hover.
This example shows hidden geometry: the channel’s boundary behind the face.
Hover or focus to reveal the element. Use Isolate element to keep it isolated.