Addaly is in open beta. Things will change, and AI answers can be wrong — check anything that matters.

Design, Before Any Software

Hierarchy, type, colour and spacing — the part of design you can do with a pencil, before any software.

Lesson 47 of 748 min

Why a near-touch is worse than an overlap

The lamp post growing out of the head

Everybody has seen the photograph where a pole rises from behind someone and appears to sprout from their skull. It is funny, and it is an instance of a general fault that also produces effects nobody finds funny and nobody can name.

A tangent is where two edges just touch, or barely overlap, or come within a hair of each other. The specific kinds:

  • A contour meeting the frame edge exactly, so the subject appears glued to the border.
  • A horizon line passing through a subject at a point where it looks attached.
  • Two objects whose outlines kiss without clearly overlapping.
  • A figure cropped exactly at a joint — the ankle, the wrist, the knee, the neck.
  • A corner of one rectangle landing on the corner of another.

The mechanism

Occlusion — one thing covering part of another — is the strongest depth cue the visual system has. It is unambiguous and it works at any distance: if A hides part of B, A is in front. Almost everything you know about the spatial arrangement of a scene starts there.

A tangent removes exactly that information. When two contours meet without clear overlap, there is no evidence about which is in front. The visual system has to resolve an ambiguity with nothing to resolve it from, and two things happen. The depth reading becomes unstable, which is mildly unpleasant in a way people describe as the image looking flat or odd. And because the contours are continuous, the gestalt principle of continuity fuses them into a single shape — which is precisely why the pole and the head become one object.

This is the near-miss problem from the first block, in another domain. Clear overlap is fine. Clear separation is fine. The narrow band between them is the fault.

Cropping at joints

The joint case deserves its own note because it comes up in every portrait and every product shot.

Cropping a figure at the ankle, wrist, elbow, knee or neck reads as amputation. Cropping mid-calf, mid-forearm or mid-thigh does not. The usual explanation is that the visual system segments a body at its joints, so a cut at a joint coincides with a boundary the brain was already treating as a division and reads as a removal, while a cut through a limb's middle reads as the frame ending.

Whatever the mechanism, the convention is old, consistent across photography and painting, and reliable. Crop through the middle of a segment, never at the hinge.

Overlap, separate, or the narrow band in betweenReads correctlyOne contour clearly covering anotherA gap wider than the smaller strokeA figure cropped mid-forearm or mid-shinTwo edges aligned exactly, on purposeReads as a faultTwo outlines that just touchA three-pixel clearanceA figure cropped at wrist, ankle or neckA shape three pixels off an exact lineA tangent removes the occlusion that tells the eye which object is in front, and continuity then fusesthe two contours into a single shape.
Overlap, separate, or the narrow band inbetweenReads correctlyOne contour clearly covering anotherA gap wider than the smaller strokeA figure cropped mid-forearm or mid-shinTwo edges aligned exactly, on purposeReads as a faultTwo outlines that just touchA three-pixel clearanceA figure cropped at wrist, ankle or neckA shape three pixels off an exact lineA tangent removes the occlusion that tells the eyewhich object is in front, and continuity then fusesthe two contours into a single shape.

Fixing it

The repair is almost always a small movement, which is what makes tangents worth learning to spot — they are cheap to fix and invisible until they are pointed out.

  • In a photograph you are taking: move the camera 30 centimetres left. That is usually the whole fix.
  • In a photograph you are given: crop slightly differently, or reposition the image within its frame so the contour clears the edge by a visible margin.
  • In a layout: either pull the elements apart until there is real space, or push them together until there is real overlap. Do not settle at a two-pixel gap.

The amount matters. A three-pixel clearance is still a tangent. Aim for a gap that is obviously a gap — at least the width of the smaller element's stroke, and usually much more.

The inspection routine

After a composition is otherwise finished, spend thirty seconds on this:

  1. Look at each of the four edges in turn, along its whole length, ignoring the middle of the image. This is unnatural and that is the point — the centre is where you have been looking all along.
  2. Find every place where two outlines come close and ask, for each, whether you can tell which is in front.
  3. Check every crop of a figure against the joints.

Doing this deliberately, as a separate pass, catches far more than looking at the image as a whole, because as a whole you see the subject and the tangents live at the periphery.

Where a tangent is a tool

Deliberate tangency is a real device. Two shapes that align exactly along an edge can read as one continuous form, which is how a great deal of logo construction works and how a layout can imply a shape that is not drawn. A subject cropped hard at the frame edge, decisively rather than marginally, reads as energetic and is a standard editorial treatment.

The difference is commitment, and it is the same distinction as between a balanced composition and one that is 5% off. Exact alignment is a decision. Three pixels away from exact alignment is a mistake. There is nothing useful in between.

The one thing to keep

A tangent removes the occlusion information the visual system uses to order depth, so two contours that nearly touch fuse into one ambiguous shape — either overlap them clearly or separate them clearly, and never crop a figure at a joint.

Before you move on

A product photograph shows a bottle whose left edge sits two pixels from the frame edge. A reviewer says it looks stuck to the border. The designer moves it to four pixels. It still looks wrong. What is the principle being missed?

Pick the one you would defend. Nobody sees your answer.

No ads. No data sale. No public scores on people. Ever.

© 2026 Addaly