The gaps between contour lines are the steepness

Close-packed rings closing in on themselves. 340, 380, 420, 460, 500 set into the line breaks as the rings tighten. A small triangle at the centre, and one more number: 517.

No name. No route drawn across it. Just the shape of the ground and the number at the top of it.

What is a contour map actually drawing?

A stack of horizontal slices through a hill, seen from directly above.

Each ring is the line where the ground crosses one fixed height — 340 metres, say, or 380 — traced around the hill and drawn flat. Stack enough of those slices on top of each other on a single sheet and the result is a shape that represents three dimensions using nothing but closed lines and a handful of printed numbers.

Why does the spacing between the rings matter more than their shape?

Because the spacing is the only thing on the page that tells you how steep the ground is.

Where the rings sit far apart, the height climbs slowly between them and the ground is close to flat. Where they crowd together — as they do here, tightening from 500 up toward the triangle at 517 — the same rise happens over far less distance, which means the hill is steeper there. Nobody has to write "steep" anywhere on the design. The rings do it by how close together they're drawn.

How many rings does a good print need?

Enough to show the crowding change from bottom to top, not necessarily every ring a full survey would record.

A full survey sheet marks a contour every few metres, which is more information than a shirt needs or can render at readable scale. What a print needs to keep is the pattern — wide gaps low down, tight gaps near the top — because that pattern is the whole argument. 340, 380, 420, 460, 500 spaced out correctly relative to each other does the job that forty intermediate rings would only crowd.

Why is there no route or name drawn on it?

Because that would make it a different object, describing a different thing.

A topo on a shirt is somebody's climb — a specific line up a specific rock face, drawn by the person who did it, first-person and personal. A contour map is the opposite kind of document: it describes the ground itself, independent of anyone who has ever stood on it. Put a route on this one and it stops being a hill and starts being somebody's day.

Can a real mountain go on it, not an invented one?

Yes — a hill's shape and its height are geography, not property.

Nobody owns the fact that a specific summit sits at a specific elevation, and nobody owns the contour convention itself; it's a drawing method, the same as a ruled table or a plotted symbol. What a mapping agency does own is its own specific published sheet — the exact line work and styling of one particular map, a different problem from naming the square you're standing in, which is agreement rather than geography. Draw your own contours from public elevation figures and the hill is yours to print.

Does this work for a hill that isn't a serious mountain?

The convention doesn't care about scale.

A local hill with forty metres of relief compresses into the same closed rings as a real summit with hundreds — what changes is how many rings there are and how tightly they pack, not the method used to draw them. A modest hill somebody walks every week is exactly as legitimate a subject as a named peak.

Isn't a shape with no name too abstract to mean anything?

Only to someone who's never climbed it.

To the person who has, the rings aren't abstract at all — they're a felt memory of exactly where the legs started working harder, translated into how close together the lines are drawn. The absence of a name isn't a loss of information; it's the design betting that the shape alone is recognisable to the one person it needs to be recognisable to.

Does it print well?

Yes — closed lines and a handful of numbers are about as forgiving as a print gets.

Keep the rings a single flat colour with a hard edge — brown or a dark earth tone on a light ground reads clearly at any size — and set the height numbers large enough to survive the weave rather than trying to match a real map's small print. One accent colour for the summit triangle is enough; more than that starts competing with the lines themselves.

How do I get one made?

Describe the hill at JustOG — how the rings should tighten, which heights to print, and where the summit triangle sits. Pick a direction, drag the crop frame, see it composited on the real garment, and it's made to order and shipped.

Designs other people have published are in the shop.

517 metres, reached by rings that never once say which way you walked up.