Datum treats MainsKeeper as an instrument for reading a fleet: a drawn wordmark, a single level line, and figures that line up. A datum is the fixed level you measure from. Here it is literal: one horizontal line at mid x-height carries the s spine, the K junction and the shared crossbar of “ee”. The same discipline runs through the equipment grid, where every reading sits on a common baseline and every uncertainty is drawn, not coloured.
Wordmark construction
Drawn on a 7-unit stroke, 34-unit x-height and 46-unit cap height, then outlined to SVG paths. Squared shoulders on the left of n and p, rounded on the right; every terminal is cut flat, horizontally or vertically, never angled.
1 The Datum K
Arm and leg do not touch the stem. They spring from a short level bar, separated from the stem by a 3-unit ink trap. The bar is the copper detail and the origin of the standalone mark.
2 One line through “ee”
The two e’s share a single crossbar that bridges the gap between them, sitting exactly on the datum. It reads as a level mains line without drawing a wave or a plug.
3–4 Cut, not curved
The M’s vertex is cut flat above the baseline; the s spine sits on the datum. Small decisions that keep the word quiet at a distance and specific up close.
Standalone mark
The Datum K lifted straight out of the wordmark, same geometry, no container. In one colour it still separates into stem and junction because of the ink trap, so it survives without the copper.
Primary · graphite + copper
One colour
On graphitePrimary lockup
Mark, a hairline rule, then the wordmark at the same cap height. The rule sits one stroke-width clear of both. Minimum size: wordmark 96 px wide; below that use the mark alone.
Light · primary
Dark
Monochrome proof · one colour, no accent
Wordmark alone · darkApp icon and favicon
The app icon is the mark on a graphite tile, copper lifted to its dark-surface value. The favicon is redrawn pixel by pixel on a 16 × 16 grid: 2-pixel stem, 1-pixel trap, 3-pixel copper bar, stepped 2-pixel diagonals with flat ends. Shown below at real size.
dock · 32 pxMainsKeeper · Fleet equipmentGrafana · HomeMainsKeeper · Duplex Utility UPSRouter admin32 px · bookmark and pinned-tab size, same pixel drawing doubledPalette
Cool white and graphite do the work. Copper appears once per view at most: selection, focus and the mark’s bar. Status colours are muted and always travel with a glyph and a word. Ratios are against #F7F7F5 unless stated.
Text floor is #6E7175 (4.6:1 on cool white). #9A9C9F and lighter are rules and fills only, never text.
Typography
Schibsted Grotesk for interface and prose; Red Hat Mono for every reading, time and identifier, with tabular figures so columns align without effort. Both OFL, fetched from google/fonts and bundled as WOFF2 in fonts/. The wordmark is drawn, not typed.
| 28 · display | Duplex Utility UPS |
| 20 · section | Recovered 15:02 |
| 16 · body | Return time unknown — sometime between 14:30 and 14:52. |
| 14 · data | BW Office UPS · Circuit B (office, separate) |
| 13 · dense | Collector contact and reading age are tracked separately. |
| 11 · label | Observed on battery |
| BW Rack UPS | 71 % | 18 min | 0 V |
| Office Desk UPS | 100 % | 42 min | 121 V |
| Duplex Utility UPS | 78 % | 29 min | 119 V |
Status glyphs and evidence marks
One geometric family at 12 px. Shape carries the meaning before colour does, so the set survives greyscale printing and colour-blind reading. Each glyph always appears with its word.
Filled diamond.
Filled triangle. Cause stays “unknown” until local evidence exists.
Filled disc.
Dashed hollow disc: we had it, we no longer do.
Solid. Observed on battery, load, charge.
Dashed, always labelled “est.”. UPS runtime, drain time.
Hollow, with the received time beside it.
Hatched, labelled with the gap.
Bracket, with the window: ±90 s.
Unsupported values read Not reported: a dashed outline and the words, never a zero and never a blank.
Proofs on light and dark
The identity has to hold on the cool-white product, on graphite terminals and printed in one colour on a label stuck to a rack.
Light · #F7F7F5 / #FFFFFFDark · #16181BOne colour · rack labelRationale
Why this is different from the six earlier concepts and from a plain admin table.
Lettering, not a symbol
Earlier marks were pictures: a ring, a feeder M, a socket, arches, a wave, a slotted square. Datum’s mark is a letter taken from its own word. Its only metaphor is a level line, and it never stands in for urgent wording.
Restraint as a tool
One accent, used for “you are here”: the open row, the focus ring, the rows that differ in a comparison. Everything urgent uses status colour plus shape plus a word, so copper never competes with a warning.
Density that reads as intent
Rules instead of cards, mono figures on shared baselines, units in their own column, two-line cells with a plain sub-label. Six UPSs and thirteen columns fit on one screen and still scan left to right.
Honest marks
Solid for measured, dashed for estimated, hollow for delayed, hatched for missing, brackets for uncertain time. The same grammar appears in the grid, the inspector, the mobile view and the CLI legend.
Assets: assets/wordmark.svg · wordmark-mono.svg · wordmark-dark.svg · logomark.svg · logomark-mono.svg · logomark-dark.svg · lockup.svg · lockup-dark.svg · lockup-mono.svg · app-icon.svg · favicon.svg. Fonts: fonts/SchibstedGrotesk-VF.woff2, fonts/RedHatMono-VF.woff2, fonts/OFL.txt.