Six knot marks for the installed icon

Three lobes, three crossings, one closed cord with no ends to soften at small sizes, drawn in the product's own casing convention — the strand passing over is redrawn on a plate-coloured casing at twice cord width, exactly as the six ladder glyphs do it. Cord is 62 units on a 512 board, which lands at 1.9px at 16px: heavy enough that the three counters stay open rather than filling in. The cord runs the ladder's full hue rotation, gold at rung one through to blaze at rung six, so the icon carries the whole day rather than one game.

Optical centring Centred on its arc-length centroid, not its bounding box. Two of the three lobes sit below the axis and hold more ink than the single lobe above, so bounding-box centring makes it sag; aligning the centroid moves the drawing 26 units — 5.2% of the canvas — off the geometric centre, and that offset is the difference between a mark that sits in the plate and one that slides down it.

One rounded-rectangle cord drawn twice, at 45° and −45°, concentric. The four crossings alternate strictly — gold over blaze north and south, blaze over gold east and west — which makes this a real two-component link and not two shapes overlapping. Both the casing and the redrawn over-strand are dash windows on the ring's own path rather than hand-traced copies, so the restored strand rejoins its own curve exactly. Cord 58 units, 1.8px at 16px. The colours are rung one and rung six: the day's first knot and its last, tied together.

Optical centring Four-fold rotational symmetry means the centroid, the bounding-box centre and the optical centre are the same point, so this is the only concept in the set that needed no compensation at all. That is not a small thing: it survives a circle mask, a squircle and a 22%-radius square identically, and the diamond counter stays dead centre in every one.

The only concept here that is not a stroke drawing. A filled disc carries the ball and a short hooked tail carries the working end; the wrapping is a mask cut through the fill, three near-vertical channels crossed by two horizontals that break where the vertical passes in front. Because it is mass rather than line there is no stroke weight to retune per size — the channels simply close up as the icon shrinks, which is either the point or the problem depending on how small you go.

Optical centring The disc is drawn off-centre — 24 units left and 12 units up — because the tail adds mass to the lower right. Centring the disc on the plate would leave the assembled mark leaning downhill; centring the assembly is what puts the disc where it looks right.

This is the only concept that could not belong to another product. The large mark is the 4×4 board with a cord threading five of its tiles and crossing itself five times; the loop closes, so there is no loose end. The small mark is the same object with the board dropped and one tile removed: four tiles, one crossing, cord raised from 36 units to 62 — 1.1px to 1.9px at 16px. That is the whole argument for a two-tier system in one pair of drawings: the rich mark's cord is a third of the small mark's, because at 192px it has to share the plate with sixteen dots and five crossings, and at 16px it has to survive alone. It is also the only concept here that was tested against three alternative simplifications — one crossing, two crossings and all five — and the one shown is simply the least bad of the four.

Optical centring Both tiers are centred on the cord, not on the board. The five visited tiles pull the loop's centroid 7 units up and left of the board's centre, so the whole assembly — dots included — is offset by that amount and then scaled to 1.12 to fill the maskable circle. The small mark's four tiles pull it 17.5 units high, and it is pushed back down by exactly that.

Maximum reduction: the moment before any knot exists, when a cord has been folded and crossed once and nothing has been pulled through yet. The eye is 236 units across against a 60-unit cord, which makes it by far the largest counter in the set — and counters, not strokes, are what fail first as an icon shrinks. The crossing is a dash window on the path itself, so the over-strand rejoins its own curve rather than a traced approximation of it.

Optical centring Set 12 units above the frame's centre. The eye occupies about half the mark's bounding box and is almost entirely empty, so it weighs far less than it measures; the dense region — the crossing and the two legs — sits low, and lifting the whole figure brings that mass toward the middle.

The only orthogonal mark in the set and the only one carrying more than two colours. It follows the constrictor's actual logic: the binding turn passes in front of the middle cord and behind the outer two, which is what makes a constrictor grip. Cord 46 units for everything, and the casings are 1.5× cord rather than the product's usual 2× — at 2× the binding's casing would nick the cord above it.

Optical centring A mark much wider than it is tall reads larger than a symmetric one of the same bounding width, so the bundle spans 61% of the canvas where every other concept spans about 78%. Held to the same width it looks like it is bursting the plate; held here it looks small, which is the honest cost of a horizontal figure inside a square.