Illustration: Teal spot

One object, shown as if it were a small physical model, sits alone on a light grey card. It reads like a product icon blown up to card size: white faces, a teal side, a crisp dark outline and a hard deep-teal shadow. Small floating extras hint at the action. Use it for empty states, feature spots and onboarding steps that need one strong object and no people.

Boundary: for a whole isometric scene of 6–8 objects on a platform slab with soft glows, use illustration-isometric-mono. For people at work, use a character style such as illustration-framed-panel or illustration-outlined-cartoon. For saturated multi-colour clusters with navy extrusions, use illustration-bold-pop.

Extracted from a set of 42 original design-and-coding cards in 14 styles; the three cards in examples/ are this style's shipped cards.

The look in one sentence

A single white object in one fixed oblique projection, teal only on its right-facing sides, outlined in 1.2 px dark teal and dropped onto flat grey by a hard, unblurred deep-teal shadow that always falls down and to the right.

Palette

Eleven colours, measured from the examples. Nothing else.

• No gradients, no opacity, no filters, no blur, no <text>: letters and digits are stroked paths.
• White faces are the majority of the object. If teal covers more than about a third of the hero's visible area, it stops being this style.
• Deep teal #0e4a48 touches the grey background only as shadow or sparkle, never as a face of the hero.

Line and fill

• Outlines: #0e3f3d, 1.2 at 480 wide, stroke-linejoin="round", round caps on open creases. Small UI parts on a card face: 1.0–1.1 with vector-effect="non-scaling-stroke" (the face transform would otherwise distort them). LEDs and tiny dots: 0.8.
• Outlines are strokes drawn over flat fills: per solid, the silhouette hull, the top ring and the vertical creases where two face colours meet. No inner contour lines on a single flat face.
• Plates (shields, clouds, bars) use the stroke-behind trick: each side quad is filled ink with a 2.9 stroke, then refilled in the side colour with a 0.5 self-stroke, then the face is drawn with a 1.2 outline. This is why stroke-width="2.9" dominates the examples.
• Shading is one tone step by facing, never a gradient:

• Glyphs: white on teal faces (2.8–5 wide), deep or ink on white and pale faces (2.4–2.8 wide), round caps and joins. A flat detail printed on a floor or face is a teal disc or rounded square with a 1.0–1.1 ink outline and a white glyph.

• Highlight streaks: two dashes, one long and one short with a gap of about 6 % of the edge, 2.2 wide (1.8–1.9 on small parts), round caps, drawn 8 units under the top edge of a white front face in pale #d8f2ed; on teal faces use teal or mid. One streak per face, at most four on the card.
• Every shadow is a hard flat #0e4a48 shape (self-stroke 0.6 to close seams). Floor shadow: the footprint pushed by SHD = [0.78, -0.48] world units per unit of height. Floating extras: the item's screen hull offset by (8.5, 7.6) px.

Characters

None. This style has no people, hands or faces. The hero object takes their place:

• One solid object. The subject is a single physical thing (a tile, a drum, a keyboard case). Ideas that are really diagrams (a git graph, a pipeline) get mounted on or built into one solid, never scattered as loose parts.
• Real thickness. Bodies are 28–40 units tall; keys and cards 8–14; coins 5.5; plates 7–8. Corners are rounded (radius 18–24 on a body, 4–9 on keys and cards).
• Detail on the front face is product detail: one highlight streak, one grey label pill (26–30 × 4.4, radius 2.2) and one teal LED (4.6–5 round, 0.8 outline) near the front-right of the top rim or the face. To lay a flat shape on the front face of a box of depth D, map its (x, z) points with pr([x, -D / 2 - 0.05, z]); on the top rim use pr([x, y, H + 0.01]).
• Action is shown by parts that lift out of the object (a key popped out of its socket, a disc raised on an arch), with the empty socket or shadow left behind.
• Give a generic shape its tell. A plain rounded box reads as "a box". Add the one feature that names the object: keycaps for a keyboard, grooves for a database drum, a finger scoop for a letter tray (scoop()), a slot for a card reader.

Decor and props

• Floating extras: 2–4, each a small solid in the same projection: a tilted UI card (about 84–114 × 50–58, 8–9 thick, tilted back 28°), a coin (radius 17–19, a digit or icon on it), an upright plate (shield, cloud, envelope; 7–8 deep). Each casts its own hard shadow (offset 8.5, 7.6) or a small ground ellipse (radius 10–17) on the floor or tile below it.
• Sparkles: 3 per card, 4-point concave stars in deep teal: a big one (size 6–7) with a small one (3.6–5) 12–16 px from it, beside one extra, and a single small one (4–5) beside an extra on the other side.
• Arc ticks: 0–3, short arcs (20–40°) hugging a floating item at its radius plus 7–9, 3.4–3.6 wide, pale-mid or teal. They say "this just moved"; Backup has none, Command K has three around its two popped keys.
• UI content on cards: grey bars 4.4 high with radius 2.2; one teal highlighted row (radius 4–6) with white bars; small square icons radius 4 in teal with a white glyph.
• Never: people, plants, outline clouds as background doodles, ground lines, platforms under the whole scene, text labels, glows.

Composition

• Background: a square full-bleed <rect width="480" height="360" fill="#ebebeb">, no rx.
• The whole group (hero, shadows, extras) is centred with its bounding box at (240, 181). It spans 58–90 % of the card width and 58–75 % of its height; margins are at least 30 px on every side. The hero alone takes about 55 % of the card.
• The hero sits slightly below centre; the extras orbit it in the top-left, top-right and left gaps, so no quadrant is empty and nothing touches the hero's outline.
• Stagger the extras at different heights (one high, one level with the hero's rim). Three extras in a level row across the top read as a toolbar, not a scatter.
• The bounding box includes every extra, so moving one extra outward shrinks the hero after centring. Read the width % that card() prints after every move and keep it at 90 % or less.
• The hard floor shadow is part of the silhouette: it extends 20–60 px down-right of the base and anchors the object.
• Structure of every example file: <rect id="P-bg">, then <g id="P-scene" transform="translate(TX TY)"> holding everything projected, then <g id="P-decor"> with sparkles and arcs in card coordinates.

Techniques

All of them come from scripts/teal3d.mjs (no dependencies, deterministic). scripts/starter.mjs builds a complete card with each one; copy both files to your work folder and edit the scene.

1. The camera. One orthographic camera for everything: makeCam({ TH: -25, PH: 36, S }), S 0.84–1.05. World +x runs to the lower right, +y away (upper right), +z up. Don't hand-draw a "roughly isometric" box: faces drift out of parallel and the set stops matching.
2. Solids and plates. solid({ fr, r0, z0, r1, z1, col }) extrudes between two rings (rrect, circle) and colours each visible side run by facing; give a smaller top ring for keycaps. slab({ fr, pts, depth, face, side }) extrudes any flat outline (shield, cloud, envelope) and returns .shadow(). mat(fr, z) maps flat 2D art onto a face: <g transform="${mat(fr, z)}">…glyph…</g>.
3. Hard shadows.

   put(`<path d="${poly(floorShadow(rrect(0, 0, W, D, R), H * 1.05))}" fill="${C.deep}"/>`); // first
   put(liftShadow(card.hull) + card.svg);                                                     // floating extra
   put(env.shadow() + env.svg);                                                               // floating plate (slab)
   put(well.onFloor(`<path d="${poly(castShadow(pts3, zFloor))}" fill="${C.deep}"/>`));     // part standing on a surface

castShadow(pts3, z, 0.6) drops a standing part's world points onto the surface it stands on (the git-graph discs on their tile). Use it only for parts that touch that surface; a floating plate cast onto the floor far below becomes a thin dark bar nowhere near the plate, so floating items always use the screen offset.

1. Recesses and wells. recess({ ring, z, depth, id: 'P-well' }) cuts an opening into a top face (teal-dark walls, mid floor, clipped; pass wall: C.mid, floor: C.pale for a large tray). well.onFloor(art) clips art to the visible floor, for printed details and cast shadows. Parts sitting inside it are drawn after it, back to front by dot(centre, cam.V). scoop({ xa, xb, depth, y0, y1, zTop }) cuts a shallow arc down through a front wall (from its outer face y0 to its inner face y1): the cut shows the floor colour, its inner faces follow the facing rule, and both edges are inked.
2. Decor. spark(x, y, size) and arc(cx, cy, r, a0, a1) in card coordinates, placed from the shifted bounding boxes that card({ prefix, scene, BOX, decor }) hands you.

Draw order: floor shadow → hero (back parts first) → face details → recesses → parts inside recesses, sorted back to front → for each extra, its shadow then its body → decor.

A torus (torus().piece()) and swept tubes (tube()) are there for rings and pipes; draw the back half of a ring before the part that passes through it and the front half after. The kit warns [fold] when a tube outline self-intersects; shorten or thicken the tube until it stops.

Failure modes

• Scattered parts read as a diagram, not a spot. Git Merge's first version was loose rings and tubes floating on grey and scored 7; mounting the same graph on one thick white tile took it to 8. Build one object.
• A teal-fronted object belongs to another set. Early Command K drafts had a teal case front; the shipped one is white on the front and top, teal only on the right side.
• A thin shadow reads as a stroke, not a drop. Backup's floor shadow was enlarged by about a quarter in its polish pass (the drum and ring footprints are pushed 40–46 units) so a solid crescent shows beyond the ring. Check that the shadow is at least 15 px wide at its widest.
• Shadows in two directions break the light. Every floor shadow, ground ellipse and floating offset goes down-right; never mirror one to balance the layout.
• Hairline seams between side colours. Without the base fill under the side runs (built into solid) a 1 px grey line shows at 2x. Keep the base fill when you write a custom solid.
• Distorted UI strokes on tilted faces. A stroke inside a mat() transform shears with the face; add vector-effect="non-scaling-stroke" to UI rects.
• Tube outlines that loop. A tight bend on a thick tube folds its silhouette into a swallowtail; the kit prints [fold]. Reduce the bend or the radius.
• Decor clutter. Background outline clouds were cut from Command K; decor is three sparkles and up to three arc ticks, nothing more.
• A big teal hole turns the hero teal. An empty tray with teal-dark walls and a mid floor read as a teal object from above (self-test, Inbox Zero). Step a large recess lighter: walls mid, floor pale.
• A plain container doesn't name itself. The self-test's empty tray read as "a tray" until a finger scoop was cut into its front wall; then it read as a letter tray at 1x.
• A floating plate's floor shadow becomes a stray bar. Casting an upright envelope onto a tray floor 90 units below gave a thin dark strip in the wrong place (self-test). Floating items use the (8.5, 7.6) screen offset.
• Extras touching the hero. A floating item whose shadow lands on the hero's outline reads as a collision; keep at least 12 px of grey between an extra (with its shadow) and the hero's silhouette.

Examples

• examples/command-k.svg: Command K. A keyboard case with a recessed key tray; the ⌘ key (teal) and the K key (pale) float above their empty sockets, a command-palette card tilts above. Shows recesses, keycaps with smaller top rings, sockets as shadows, a tilted UI card.
• examples/git-merge.svg: Git Merge. A thick white tile carrying a square-bar git graph; a teal branch arches up through a raised commit disc and plugs into the merge disc. Shows shadows cast on a tile top (clipped to it), commit discs, a PR card and a commit coin with ground ellipses.
• examples/backup.svg: Backup. A three-disc database drum wearing a lifebuoy (torus split into white and teal bands), with a shield-check plate, a cloud-upload plate and two data coins (1 and 0). Shows cylinders with grooves, a torus drawn in back and front halves, a shadow cast onto the drum, upright plates.

Workflow

Run commands from this skill's folder. WORK is your own work folder (any path); the card is $WORK/card.svg with id prefix xx-.

1. Brief. Name the subject and the one object that embodies it. Write one line: hero object, the part that moves or lifts out, 2–4 extras that support the subject. If the subject is a process, find the physical object that holds it.
2. Set up the generator.

   mkdir -p "$WORK" && cp scripts/teal3d.mjs scripts/starter.mjs "$WORK/" && mv "$WORK/starter.mjs" "$WORK/gen.mjs"

Change P to your prefix and the label.

1. Block the hero with solid and slab only (no details), render, and check the silhouette and the shadow read at 1x.
2. Draw face details, recesses, lifted parts, then the extras and decor. Keep the draw order above.
3. Render (headless, 2x): node "$WORK/gen.mjs" "$WORK/card.svg" && node scripts/render.mjs "$WORK/card.svg" "$WORK/card.png"
4. Sheet next to the examples: node scripts/render.mjs --sheet "$WORK/sheet.png" examples/*.svg "$WORK/card.svg". Ask "same hand, same set?": face colours, outline weight, shadow direction and size, amount of white.
5. Zoom the places faults hide, re-rendered from vector: node scripts/render.mjs "$WORK/card.svg" "$WORK/z1.png" --zoom x,y,w,h --scale 8. Check creases where colours meet, recess edges, glyphs on faces and every shadow edge.
6. Critique against the five criteria in references/craft.md (criterion 2 becomes "the hero object's construction": thickness, corners, product detail, believable parts). Fix and repeat; expect three or more rounds.
7. Lint: node scripts/lint.mjs "$WORK/card.svg" --prefix xx- --palette style.json. Fix every ERROR. In this style there should be no off-palette WARN at all.

references/craft.md holds the file contract, originality rules and scoring that apply to every illustration style.

Verify

• [ ] Background is one #ebebeb full-bleed rect without rx; nothing else touches the card edge.
• [ ] Exactly one hero object; no person, plant, platform or ground line.
• [ ] Every face is flat: top and front of the hero white, its right side teal; pale parts have pale sides and a mid right side.
• [ ] All outlines are #0e3f3d at 1.2 (UI 1.0–1.1, LEDs 0.8); no outline in any other colour.
• [ ] Every shadow is flat #0e4a48 and falls down-right; the floor shadow is at least 15 px wide at its widest.
• [ ] Every floating extra has its own hard shadow or ground ellipse, in the same direction.
• [ ] 2–4 extras, 3 sparkles (one big-small pair plus a single), 0–3 arc ticks.
• [ ] Group bounding box centred at about (240, 181), 58–90 % of the width, margins ≥ 30 px.
• [ ] One highlight streak per white front face (long dash + short dash, pale, 2.2).
• [ ] Glyphs and digits are stroked paths with round caps; no <text>.
• [ ] At 8x, no hairline seam between side colours and no gap between a fill and its outline.
• [ ] Only the 11 palette colours appear (lint.mjs --palette style.json prints no WARN).
• [ ] The subject reads at 1x without a caption.