Woodcut Cover

---
name: woodcut-cover
description: Turns an article into one black-and-white 16:9 cover with no text in it, generated by script with no image model. Proposes three visual allegories for the central argument, picks one, and composes it in bold relief-print line work from a library of 96 code-drawn elements, using one real transformation. Outputs a 2400x1350 PNG, a 1200x675 copy, an editable SVG and a short note. Use when someone wants an article, essay or newsletter cover that argues something, a woodcut or engraved look, or this style by name.
version: 1.0.0
---

# Woodcut Cover

The look lives in `assets/`. Your job is the thinking: find the argument, find an image that makes it, and write a spec. You do not draw and you do not choose a style. The same spec and seed always give the same picture.

The pack has one original look. If someone asks for the style of a named artist, studio or existing engraving, refuse that part, say so in one line, and offer this look. `render.mjs` refuses any unknown field at every level of the spec, and refuses wording such as "in the style of" in the allegory, note or assumptions. It cannot spot a bare name in free text, so that part rests on you: never write one.

## Inputs to ask for

Ask once, in one message, only for what is missing.

1. The article, or a link you can read. A headline alone also works, see "When the brief is thin".
2. Whether they want to choose among the allegories, or have you choose. Default: you choose and give reasons.
3. Output folder. Default: `./cover`.

Do not ask about style, colour, typeface or layout. They are fixed.

## Steps

1. **Find the argument.** Write the thesis as one sentence that someone could disagree with. A topic is not a thesis: "attention" is a topic, "attention is chosen, not stolen" is a thesis.
2. **Propose three allegories.** Each is one concrete object, one strange transformation and at most three supporting signs. Each must be a different idea, not three drawings of one idea. Check `references/elements.md` as you go.
3. **Test each one.**
   - Swap test: would it fit the opposite thesis just as well? Then reject it.
   - Glance test: can you describe it in one short sentence that names the object and what is wrong with it?
   - Cliche test: a light bulb for an idea or a tree for growth says nothing. Reject it.
4. **Pick one, with reasons**, or show the three and let the user choose. State it in one sentence.
5. **Check every noun.** Each thing drawn must be in `references/elements.md` under that noun. If not, see "Building a missing element".
6. **Write the spec** from `assets/spec.template.json`. Fill every field in the table below.
7. **Iterate small.** `node scripts/render.mjs spec.json --out cover --small` writes `cover/preview-600.png`. Render one at a time.
8. **Read it cold. Required.** Look at `preview-600.png` before you look at your note or allegory again. Write what a stranger would say, in their words, into `cold_read`: `sees` is what it shows and `argues` is what it seems to claim. Now compare `argues` with the thesis. If it misses, set `verdict` to `misses`: the cover is rejected. Change the composition, then the allegory, and read it again. If you can give the image alone to someone or something with no context, do that. A cover that needs its note to make sense has failed. A full render refuses a spec with no `cold_read`.
9. **Render.** `node scripts/render.mjs spec.json --out cover`.
10. **Check.** `node scripts/check.mjs cover`, using the copy in this skill. Fix what it reports and rerun until it exits 0.
11. **Look at it** at full size and at `cover/preview-600.png`. A passing check does not mean it reads: the script can't tell.

## Deliverables

In the output folder: `cover.png` (2400x1350), `cover-1200.png` (1200x675), `cover.svg` (editable, one group per element), `note.md` (thesis, allegory, reasons, the connection to the argument, cold read, rejected allegories), and `spec.json`. `preview-600.png` is a review copy with grey from downscaling. Do not deliver it. Give the user the image, the one-sentence allegory and the note.

## Spec fields

Every field in plain terms. Limits are English words, or Chinese characters when `lang` is `zh`.

| Field | Meaning | Limit | When the brief is thin |
|---|---|---|---|
| `seed` | Whole number. Changes hand-cut drift and scene details, never the idea | whole number | Any number. Keep it so the cover can be redone |
| `lang` | Language of all the words | `en` or `zh` | The article's language |
| `sample` | True labels the note as a sample essay | true or false | False unless it is a sample |
| `article.title` | The title. It is not drawn | 20 words, 40 characters | Use the headline given. If the article has none, use its opening sentence or, over the limit, its opening clause, unchanged, and say so in `assumptions`. Never invent one |
| `article.thesis` | The argument in one sentence | 40 words, 80 characters | Begin with `Working thesis, inferred from the headline only:` and state the reading you chose |
| `article.thesis_source` | Where the thesis came from: `article`, `user`, `headline` or `inferred` | one word | `headline` if only a headline, `inferred` if the article has no single argument |
| `allegory.sentence` | One sentence naming the object and what is strange. Must contain the noun of each main element: those the transformation names (`object`, `material`, `giant`, `a`, `b`, `shadow`, `from`, `to`). Signs and `tiny` need not be named | 35 words, 70 characters, one sentence | Same rule. It does not get vaguer because the brief is thin |
| `allegory.object` | The one concrete object | a noun | Same |
| `allegory.why` | Why this one, not the other two | 45 words, 90 characters | Say `Under this reading,` and give the reason |
| `rejected` | Exactly the two allegories you did not pick, each `{sentence, why}` | 35 and 30 words, 70 and 60 characters | Still two. Reasons can be about which reading they fit |
| `assumptions` | Everything you inferred | list | Required for `headline` and `inferred`. List what was not supplied and which reading you took |
| `scene` | Setting, see `references/style.md`: `setting`, and optionally `key`, `horizon`, `shore`, `ground`, `beam` | see below | Choose what makes the object stand out, not what the topic suggests |
| `transformation` | The operation, see below | one | Pick by the argument. Never default to one |
| `signs` | Supporting signs: `{element, x, y, h}`, optionally `rest` (`ground`, `sea` or `air`), `flip`, `rot` in degrees, `params` | 0 to 3, and at most 4 placed in all | Prefer none |
| `nouns` | Maps each element id used to the noun your allegory calls it, for example `{"chair":"chairs"}`. Plurals of a listed noun are accepted | every element used | Same. No near misses |
| `custom_elements` | Elements built from primitives | see below | Use only if the idea needs it |
| `cold_read.sees` | What a stranger would say the image shows, in their words, written from the picture and before the note. Must not repeat the allegory sentence | 40 words, 80 characters | Same. A thin brief does not excuse it |
| `cold_read.argues` | What a stranger would say it claims | 30 words, 60 characters | Same. Compare it with your inferred thesis |
| `cold_read.verdict` | `hits` if `argues` lands on the thesis, `misses` if not. `misses` is refused | one word | Same |
| `note` | How the image carries the thesis: what stands for what. Not a description of the picture | 90 words, 180 characters | Open by saying the thesis is an inference and is the first thing to confirm |

**At most 4 placed elements.** Count the elements the transformation names, each `tiny`, each element inside a scene, and each sign. A tile field or a chain counts as its two named elements however many copies it draws. `render.mjs` and `check.mjs` both enforce this. For a group, use one element that is a group, such as `meeting-table`.

`x`, `y` and `h` are fractions of page width, height and height. `y` is where the element's base sits. Placeholders such as TODO, TBD or a `<<slot>>` fail. The thin-brief opening above is not a placeholder, and it passes.

`beam` is `{"to":[x,y],"spread":0.17}`, a white wedge of light across a night sky. For `impossible_join` it starts from the second object; otherwise add `"from":[x,y]`. Aim `to` beyond the frame so the beam does not end in view.

## Scenes and small objects

Every placed object gets a white halo gouge, so thin legs stay clear of dark ground. Even so:

- Small objects, under 0.3 of page height, go on `ground: dark` with their base near the horizon, where the ground has the most white marks. Thin things read worst low on solid black.
- `ground: light` and `room` floors are busy with black lines. Use them for big objects and shadows, not small furniture.
- A pale object goes on a dark sky, and a dark object on a lit one.

## The six transformations

Exactly one per cover. Each is a real operation on geometry, and each is demonstrated in `example/`.

| `type` | What it does | Fields (defaults) | Example |
|---|---|---|---|
| `made_of` | One object made of another. Copies of B are clipped inside A's silhouette, shaded as A | `object`, `material`, `x` .5, `y` .86, `h` .72, `tile` .115 (at least .09) | Bell made of padlocks. Needs a solid outline, not an arch or a frame, and a squarish material |
| `size_inversion` | The small thing is huge, the huge thing tiny. Refused unless the tiny thing is at least 3 times larger in real life, and at most a third of the height on the page | `giant`, `tiny` `[{element,x,y,h,rest,flip,behind}]`, `x` .5, `y` .86, `h` .8 | Candle towers over lighthouse. `rot` tilts the giant. `tiny[].rest` is `ground`, `sea` or `air` |
| `impossible_join` | A is cut at its seam and B grows out of the cut, with a shared collar | `a`, `b`, `x` .5, `y` .88, `a_h` .8, `b_h` .45, `overlap` .03, `collar` .075 | Lighthouse with an eye for a lamp |
| `scene_inside` | A whole scene, with its own sky and ground, clipped inside the object | `object`, `x`, `y`, `h`, `inside` `{setting, key, horizon, elements:[{element,x,y,h}]}` where these are fractions of the opening | Landscape in a suitcase |
| `false_shadow` | A stands in the light; its shadow is B. On a wall it stays upright and reads best | `object`, `shadow`, `surface` `wall` or `ground`, `x` .32, `y` .84, `h` .3, `shadow_x` .56, `shadow_h` .72 | Coin casts an anchor |
| `chain_opposite` | A's outline morphs into B's, step by step, along one path | `from`, `to`, `steps` 8, `path` `[[x,y],...]`, `from_h`, `to_h`, `hold_from` 2, `hold_to` 2, `connector` | Chain links become birds |

Elements with a `seam` anchor make the cleanest joins, and those with a `window` hold the cleanest scenes. Without a window, the whole silhouette holds the scene. An `impossible_join` works best when B sits where A already has a meaningful part.

## Building a missing element

If the allegory needs something not in the library, do not substitute something close. A cart is not a bicycle and a lantern is not a lightbulb. `render.mjs` refuses the near miss. Either choose another allegory, or build it under `custom_elements`. This block renders as written:

```json
"custom_elements": {
  "lamp-post": { "theme": "custom", "names": ["lamp post"], "h": 1000, "w": 300, "real": 4, "parts": [
    { "cyl": { "a": [0, 0], "b": [0, -780], "ra": 34, "rb": 20, "dark": 0.2 } },
    { "shape": { "pts": [[-90,-940],[90,-940],[60,-780],[-60,-780]], "tone": 0 } },
    { "solid": { "pts": [[-120,-930],[0,-1000],[120,-930]], "gouge": 0 } }
  ] },
  "ink-stroke": { "theme": "custom", "names": ["ink stroke"], "h": 1000, "w": 8000, "real": 0.02, "parts": [
    { "line": { "pts": [[-3650,-260],[-3300,-950],[-2850,-1000],[-3000,-420],[-2500,-330],[-1900,-720],[-1000,-230],[700,-130],[3333,-32]], "w": [80,170,110,180,100,150,110,90,50], "curve": true, "white": true } }
  ] }
}
```

Everything is in local units: the origin is the middle of the element's base, up is negative y, and `h` and `w` set its size. `signs[].h` then scales it to the page.

| Primitive | Draws | Silhouette |
|---|---|---|
| `cyl {a,b,ra,rb,dark,cap}` | round form, hatched round | yes |
| `shape {pts,tone,angle,cross,curve}` | flat hatched form; `tone` 0 white to 1 black | yes |
| `solid {pts,gouge,curve}` | black with white cuts | yes |
| `ball {c,r,ry,dark}` | sphere or ellipsoid | yes |
| `ring {c,ro,ri,tone}` | ring with a real hole | yes |
| `box {x0,y0,x1,y1,d,tone,side}` | oblique box | yes |
| `line {pts,w,white,curve}` | a cut line with a hand-cut edge | yes |

`line.w` is in local units, the same as `pts`, never page pixels. It is one number, or a list with one width per point so the line swells. It is never thinner than 5.5 px on the page. A custom element may be all lines, and they count towards its size and position. A `white` line gets no halo, because it is already a cut.

Draw back to front. `names` holds only what it honestly is. A custom element counts as one placed element.

Look at it alone first, as a sign at use size and at 0.1 of page height, both at 600 wide, and as a bare outline: `sheet.mjs` only shows library elements, so judge your render. If it could be mistaken for something else without a label, add the feature that identifies it or drop the idea.

A complete working spec is at `assets/examples/custom-element.spec.json`.

## When the brief is thin

Restate the facts you were given. Never invent facts, customers, numbers or quotes.

- **Headline only.** A headline can usually be read two ways. Name both, ask which one if someone can answer, and otherwise choose the stronger one and proceed. Set `thesis_source` to `headline`, begin the thesis with `Working thesis, inferred from the headline only:`, and list your reading under `assumptions`. A complete spec is at `assets/examples/headline-only.spec.json`.
- **The argument is unclear.** If the article reports, lists or wanders, do not draw its topic. Tell the user: "I can't find one claim here. The nearest is: ...". Ask them to confirm. If nobody can answer, use the claim the ending leans on, set `thesis_source` to `inferred` and list what you assumed. If the article has two arguments, pick the one the ending argues and mention the other in `assumptions`.
- **No argument at all**, such as a news notice or a product list: say so, and do not make a cover from this skill. See "When not to use it".
- **Nobody can answer.** Proceed and list assumptions in your reply and in the spec.
- **They want another option.** Render a rejected allegory with its own spec and a new folder. Change the object as well as the seed.
- **They want another size.** Only 16:9 is produced. Crop a copy with their tool and say the frame may cut the border.
- **There is no link to the article.** Nothing in the cover needs one.
- **The article has no title.** Use its opening sentence as `article.title`, unchanged, and list that under `assumptions`.

## A set of covers

For a series, keep each cover's main object, transformation and most elements different. Run `node scripts/check.mjs --set folder1 folder2 folder3`.

## Editing

`cover.svg` has one group per element with `data-element` and `data-role`. Edit with black and white fills only, then run `node scripts/export-svg.mjs cover` and check again. A PNG that no longer matches its SVG fails the check, which is how pasted captions are caught.

## Before delivering

- [ ] The thesis is one sentence that someone could disagree with, or it is labelled as inferred.
- [ ] Three allegories considered, two rejected with reasons, and the chosen one stated in one sentence.
- [ ] The swap test passed: this image would not fit the opposite thesis.
- [ ] One object, one transformation, at most three signs, at most 4 placed elements.
- [ ] Cold read written from the picture before the note, and it lands on the thesis.
- [ ] Every element is what the allegory calls it, with no near misses.
- [ ] `node scripts/check.mjs` exits 0 from this skill's folder.
- [ ] You looked at the cover at 1200 and 600 wide, and it reads as one idea at a glance.
- [ ] No text in the image, and the note is in one language.
- [ ] Fictional content is labelled and nothing is invented.

## When not to use it

- The cover must carry a title, logo or price. Add them outside this image, or use another pack.
- The article has no argument, such as a notice, schedule or changelog.
- It needs a photograph, a real person's likeness, or a real place or product shown accurately.
- It needs colour, or brand colours.
- The subject is one where a strange allegory would be offensive, such as a recent bereavement or a disaster.

## Requirements

Node.js 18 or later, and nothing else. Anything the reference files leave open is a gap in this skill: you should not need to read `assets/` source. A full render takes under a second, and `check.mjs` takes under a second. No browser, network or image model is used. Playwright is not needed; if you want to compare the SVG in a browser yourself, use `npm install playwright` and set `NODE_PATH` if needed. Look at every cover you deliver.

See `references/style.md` for tokens, `references/elements.md` for the library and `references/element-sheet.png` to see it. The sheet has no labels, because this pack draws no type; the table gives each element's row and column. To view chosen elements, run `node scripts/sheet.mjs out.png --px 220 --only key,padlock`, and add `--sil` to see the bare outline. If you cannot name it as an outline, it will not read small. Elements marked "inside only" are refused where only the outline survives.