Invented fish rendered with curved fins, overlapping scale arcs and fine etched lines

A parameterized body envelope anchors the fins, tail, scales, gills and eye. Curved fin rims connect to the body along a root span, while varying scale arcs and fine hatching create an invented specimen entirely from editable vector strokes. The body and engraving details are generated locally without image-service calls. Larger canvases and denser scales increase local drawing work; no photographic specimen is required.

Needs
Python 3

v1.0.0 · Updated Oct 25, 2026 · 736 KB · Use it for personal and client work; please don't resell or share the package.

What you get

  1. Imaginary-specimen PNG and editable stroke SVG

  2. Body, scale and fin geometry ledger

  3. Portable brief and local artwork proof

Good for

  • Imaginary natural-history illustrations
  • Exploring creature proportions and etched line structure

Not for

  • Identifying or accurately documenting a real species
  • Biological anatomy verification

How it works

Includes a local renderer

  1. Choose the input

    Choose an imagined body proportion and fin character.

  2. Render and inspect

    Construct the continuous body, organic fin rims and etched surface detail.

  3. Adjust and export

    Inspect the silhouette and line density, then export the vector specimen.

How the workflow runs

How Invented specimen etching works

A parameterized body envelope anchors the fins, tail, scales, gills and eye. Curved fin rims connect to the body along a root span, while varying scale arcs and fine hatching create an invented specimen entirely from editable vector strokes.

What's inside the skill

What you can change

  • body_ratio: 0.22–0.55 of canvas height
  • fin_spread: 0.5–1.35
  • scale_density: 14–42 body columns
  • seed and paper, ink and accent colors

What to review before delivery

  • The body ledger contains 600 contour vertices.
  • The example and changed proportions produce more than 30 actual scale centers.
  • The saved brief reproduces the PNG and SVG; unsafe replacement is rejected.

See the package files

These are selected working files from this edition, with their actual role. The complete download also contains instructions and applicable license notices.

  • The domain algorithm and invariant checks.

    scripts/recipe.py
  • Runnable, editable example parameters.

    examples/brief.json
  • Control meanings, proof interpretation and limits.

    references/design-notes.md

Why use this skill

Start with this package

The package constructs the creature itself and exposes its geometry. It saves writing the body, fin-ray and scale logic instead of asking for a generic engraving-style image.

Compare the options

A prompt, your own skill, or this workflow?

Start with a prompt

Your agent can create from a plain request. The brief, visual rules, asset choices, output format and review process still need to be established for that project.

Write your own skill

You choose and maintain the reusable instructions, defaults, file structure and checks. This is useful when your process needs different rules or integrations.

A workflow created for PopNow

This workflow was built for PopNow. Its source files, included dependencies and applicable notices are part of the package; the scope described below belongs to this edition.

Guide reviewed Oct 25, 2026

What will this cost?

The body and engraving details are generated locally without image-service calls. Larger canvases and denser scales increase local drawing work; no photographic specimen is required.

The supplied route runs locally. A new-media request is a separate choice. Free skill. New media is quoted before it runs.

The skill package

Free to install under your account's download allowance. The package license covers your own and client work; redistribution is excluded.

Existing assets and local work

Reusing suitable assets, editing files and running local assembly do not call a PopNow generation model. Your computer and any required runtime still do the work.

Your agent and hosting

Any subscription, hosted computer, deployment or other provider fee belongs to that service. Installing this skill does not include those services.

How PopNow billing works

Connections using a PopNow API key, including API-key MCP connections, spend from the separate API balance in USD. A ChatGPT or Claude connection authorized through OAuth spends website credits. These balances are separate; the quote shown by your connection is the approval basis.

Download allowances and current account conditions apply. A free package does not mean unlimited free generation.

How to use it

You say

  • Use the PopNow skill "Invented specimen etching" (invented-specimen-etching) for this: Choose an imagined body proportion and fin character. Use the packaged example as a starting point and return the actual artwork with its editable inputs.

Then try

  • Rebuild a visibly different version using body_ratio: 0.37 → 0.38; fin_spread: 1.08 → 1.2.

  • Explain the result using its actual proof files and algorithm ledger.

What to have ready

  • A body proportion, fin spread and line palette
  • Python 3.10+, Pillow and NumPy

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Questions

Is this a scientifically accurate species?

No. It is an intentionally invented fish. The ledger marks the biological identity as imaginary; the body and fin parameters are art controls, not verified anatomical measurements.

Can I edit the scales and fins?

Yes. SVG strokes are individually editable, and the brief changes body thickness, fin spread, scale density and colors. The rendered fish is not a pre-generated image placed inside a frame.

What costs depend on this workflow?

The body and engraving details are generated locally without image-service calls. Larger canvases and denser scales increase local drawing work; no photographic specimen is required.

What is already packaged in Invented specimen etching?

The domain algorithm and invariant checks. Runnable, editable example parameters. Control meanings, proof interpretation and limits.

Which parts of Invented specimen etching can add a charge?

The body and engraving details are generated locally without image-service calls. Larger canvases and denser scales increase local drawing work; no photographic specimen is required. Connections using a PopNow API key, including API-key MCP connections, spend from the separate API balance in USD. A ChatGPT or Claude connection authorized through OAuth spends website credits. These balances are separate; the quote shown by your connection is the approval basis.

How does Invented specimen etching differ from writing a prompt or my own skill?

The package constructs the creature itself and exposes its geometry. It saves writing the body, fin-ray and scale logic instead of asking for a generic engraving-style image.