Scratch Film — Style Prompt

Direct animation: every picture looks scratched through black emulsion with a needle and tinted with transparent dye, redrawn by hand fifteen times a second and projected. Black is the ground; everything bright is a cut. Lines boil from drawing to drawing, light glows through every cut, colour lies in the grooves like dye. References (grammar only): the direct-animation tradition (films scratched and painted straight onto the film stock, without a camera), its boiling line and its light through the cut. Take the look of the marks and the projected glow; never copy a frame, a character or a score from any existing film, and never name one.

1. Essence, and what it is not

These define the style; keep all of them.

• Black is the ground, light is a cut. The frame is warm black emulsion. Everything bright is a scratch (one cream colour); everything coloured is transparent dye laid in or beside the cuts. A bright area is dense hatching, never a flat fill.
• The line boils. Each drawing is redrawn with a new hand tremble at 15 drawings a second: several near-parallel passes per line, uneven width, skips, chipped edges, an overshoot tail. Even a held frame moves.
• The whole frame is the drawing. Sea, sky, a room, a map: the world itself is scratched and dyed, edge to edge. The style is not a strip of film shown inside a scene.
• The cut is visible. Marks appear behind a hot point (a white core, a glow, chips flying): the act of making is part of the picture.

Not a chalkboard or whiteboard explainer (no flat board, no clean vector strokes), not Ink Wash (no wet tonal washes, no paper), not ASCII / CRT (no raster, no character cells), not a neon sign (no tubes), not a collage (no photographs). Film props are not the subject: perforations, frame lines, film strips, projectors and countdown leaders appear only if a story is about film itself, never as decoration.

2. Materials & rendering

Reference: how our engine does it (demo/js/base.js); another stack is fine if the marks read the same.

• Layers. One 2D canvas per frame: a mottled emulsion plate (warm and cool blotches, a rotating set of four), the scene's marks in painter's order, then the light pass: two blurred additive copies for halation (about 9 px and 28 px at 1080p), dust specks and short curls, a corner falloff, a one-drawing flicker, a weave of about 1 px, grain added at mastering. No long vertical hairlines (they read as film damage).
• The needle line (scratch): a Catmull-Rom path resampled in screen space, 2–3 passes offset by the tremble, width varying along the stroke, about 1 % skips, small triangular chips on heavy lines, a thin overshoot tail. Width follows the picture's scale; the tremble is in screen pixels (about 0.7 × width, capped at 5 px), so a close-up and a wide shot both look hand-cut.
• Dye (dye): 4–8 thin translucent bristles along a path, tapered at both ends: reflections, rays, wakes.
• Fills (hatch): back-and-forth zigzag hatching that overshoots the outline, two passes at different angles. Large light (a sky, a glow from above) is several sparse hatch layers stacked into a gradient, or drawn on its own layer and faded with a gradient mask; never stepped bands (they read as film frames).
• Text as cuts. Words are rendered once as images with thin skips through them and cut in left to right behind the hot point; they tremble by less than a pixel and are never re-lettered per drawing.
• Depth. Depth of field is a blurred copy masked by a disc around the subject; background creatures can be drawn on their own layer and blurred. Keep blur ≤ 5 px on bright hatching or it melts into a flat fill.

3. Colour logic

• Ground: warm black #050403 with brown and blue mottles; never grey.
• Light: one cream #FFF4DC for every cut. Strong light (a sun, a glow from above, the hot point) is the same cream, denser.
• Dye: a few transparent colours laid by hand, alpha 0.5–0.9, always with cream lines on top. One dye, one kind of thing, for the whole film. Our demo: teal #1FB39A the hero, blue #2F86FF living light, red #FF3220 danger, yellow #FFC81C sun and moon, green #46D65A small food.
• Values: black dominates (≥ 50 % of most frames); the brightest point is a fresh cut or a light source.

4. Type & subtitles

• Words belong to the drawing: a depth figure beside a scratched ruler, a title cut into the dark. No boxes, no outlines, no drop shadows.
• Faces (all OFL): a heavy geometric sans filled with diagonal cuts for titles (Jost 800), a sturdy mono for numbers (IBM Plex Mono SemiBold), a marker-like Chinese face (LXGW Marker Gothic). These are references; any face with the same roles works.
• Subtitles sit low left, Chinese above English, cream on the black ground, revealed left to right in about 0.3 s. Cap height ≥ 30 px for anything the viewer must read.

5. Motion quality

• Everything steps on twos: 15 drawings a second at 30 fps. Each drawing reseeds the tremble.
• Camera moves and characters move on the same steps; a stepped camera is part of the look, but keep it smooth in time (eased), not jerky in position.
• Cuts appear progressively behind the hot point; dye sweeps in behind a brush edge; lights switch on with a short bloom.
• Characters: anticipation, a flick, follow-through (2–4 drawing anticipation, big poses held 4–6 drawings).
• At a cut between shots, nothing jumps: the same subject keeps its place, size and angle across the cut, new elements come in after it.

6. Camera grammar

• Keep the subject ≥ 1/3 of the frame; never hold a frame that is mostly empty black for more than a second without a mark being made.
• Transitions happen inside the medium: a cut line that becomes a divider, a push into a point of light, a pull to a wide shot. No wipes, no page turns, no white flashes.

7. Sound palette

Reference, not rule: - Hand-made instruments: struck and bowed vibraphone, glockenspiel for each new light, pizzicato double bass, log drum for a threat, brushes. Avoid generic piano and strings. - The cut is heard: a gritty high scrape with a thin wandering squeal, a dry tick per small mark. - Drawn tones: a sine read at 24 drawings a second flutters like a hand-drawn sound stripe; good under each light that switches on. - Silence: cutting all music before a key moment is the strongest accent; the first sound after it should be a mark being made.

8. Native moves

• Scratch-in. A line or a whole character cut live behind the hot point. Fits content like: a title; a first diagram line; a character being born; a correction.
• Hatching is light. A light source is a field of hatching; an uncut shape inside it is a shadow; hatching that fills the shape makes the shadow vanish. Fits content like: a searchlight; being seen; switching something on.
• One mark to a whole place. A single drawn subject becomes one of thousands of glowing points in one continuous pull, each level of detail appearing only while it suits the frame. Fits content like: a city's population; crowds; networks; "you are not alone".
• Lights on, one by one. A row of dots each switching on with a bloom and a note. Fits content like: a sequence; a count; a signal; a city at dusk.
• A cut across the horizon. The scene's key line (a horizon, a road, a timeline) cut from one edge to the other, opening and closing a film.

Our demo opens on a cut across the horizon, uses hatching is light and lights on, one by one as its turn and one mark to a whole place as its climax, and ends on the horizon line again with every light gone dark but one point. A new film opens and ends another way: a title cut letter by letter, a split screen with two views on one beat, a single point of light pushed into, or an ending on the last mark held until the dust settles.

9. Pitfalls of the medium

• Flat bright areas look digital: always hatch; stack sparse layers for gradients.
• Large light drawn as segments or bands reads as film frames: fade it with a mask instead.
• Tremble scaled with zoom shakes macros and blurs wide shots: tremble in screen pixels, width from the picture.
• Boiling text becomes unreadable: tremble ≤ 1 px on text, never re-letter a word per drawing.
• Too many full characters overlapping on screen turn into noise: fewer, smaller, placed by hand around the hero.
• Particles positioned by speed × absolute time jump whenever the speed changes: offset them by the camera's displacement instead.
• A crowd of glowing points generated in boxes shows the box edges: use soft (Gaussian) distributions per level of detail.

10. Engine

• demo/js/base.js: maths, scratch, dye, hatch, glow, emulsion / dust / grain plates.
• demo/js/creatures.js: characters drawn in their own units and mapped anywhere (MAPF); a scratch-in order for the hero; a silhouette that is filled segment by segment.
• demo/js/main.js: render(t) stepping on twos, depth of field, halation, dust, flicker, weave, subtitles, TEXTS, EV.
• Minimal example, not in the demo: a horizon cut left to right on black, with a hatched sun.

const hz = 600, p = eo(seg(t, 0, 1));                       // cut the horizon in one second
const P = []; for (let x = -30; x <= -30 + (W + 60) * p; x += 30) P.push([x, hz + 1.5 * Math.sin(x * .02 + dn)]);
scratch(P, { w: 4, tail: false }); if (p < 1) tipSpark(...P[P.length - 1], dn, 46);
hatch(ringPts(1200, hz - 60, 66, 66, 30), YEL, { gap: 6, a: .85, ang: .5, lw: [1.4, 3.4] });

11. Variation space

Decide per film: what is scratched (a creature, a map, a machine, letters), which dyes mean what, how much of the world is shown, tempo and instruments, whether the camera travels or stays.

• Structures: one journey ending in a scale reveal; a countdown of lights; a call and response between two drawn voices; a map growing line by line.
• Openings: a horizon cut across the black; a single point of light pushed into; a title cut letter by letter.
• Endings: the opening line cut again in another colour; everything that glowed going dark but one point; the last mark held until the dust settles.

How our demo was made (story, shots, score, end card, build): DEMO.md. Read it after your treatment exists.