Plinth — logo development sheet

Working file, kept alongside the finished suite so the reasoning shows. Concepts first, then the winner's iteration, then the full suite tested at size and against every palette it has to survive.

1 — Three concepts

All three literal: a goniometer (range-of-motion measurement, used across all three disciplines), a postural plumb line (the alignment tool physios and chiropractors both still use), and the plinth itself — the treatment table the trade takes its name from.

Goniometer P
The bowl is a measurement arc; the pointer is the reading. Doubles as an actual monogram, which the other two don't.

Winner

Plumb line
Strong trade reference, but reads as an abstract instrument rather than a mark — harder to own as "the Plinth P" the way concept 1 does.

Runner-up

The plinth, in profile
Most literal. Reads as furniture, not a mark, once reduced past ~48px — the table top and leg lose their meaning and it becomes a generic glyph.

Cut

2 — Iterating the winner

Draft 1
Proportions untuned — bowl too small relative to the stem, pointer collides visually with the roundel edge.

Draft 2
Taller stem for a true P proportion, heavier primary stroke, pointer angle opened so the dot clears the edge with real margin.

Final
Optically re-centred — the bowl's visual weight sits right of the stem, so the whole mark shifts left of true centre to balance. Fixed teal→ink gradient, palette-neutral by construction.

Shipped

3 — The suite

Primary lockup

Stacked lockup

Icon mark alone

Monochrome, on dark

Monochrome, on light

Reversed, on brand field

Favicon at 32px

4 — Legible at 24px?

The icon mark alone, at the sizes it actually ships at. Below 32px the pointer/dot are simplified out (that's the favicon variant); the letterform itself has to survive down to 16px browser-tab scale.

5 — Against all six palettes

The mark's fixed gradient (teal → ink) against every background and surface colour it will actually sit on. It never reads the palette CSS, so this is the honest test: does the fixed colour survive next to each one, not does it match.

Left to right: Harbour Teal, Slate & Rust, Sage Clinical — light, then the same three in dark. The roundel's own fill means the mark never depends on the page underneath it for contrast.