Book Cover Design

Book cover design with genre-specific conventions, typography rules, and AI image generation. Covers fiction and non-fiction genres, sizing, thumbnail testin...

Security Scan

The skill's purpose (book-cover design with AI image generation) matches its instructions, but it instructs users to run a remote installer and to authenticate with a third-party CLI without declaring credentials or explaining privacy/credential handling — these mismatches and the curl | sh install pattern are concerning.

Purpose & Capability

The skill is about book-cover design and uses an external image-generation CLI (inference.sh), which is a plausible dependency. However, the SKILL.md instructs the user to run 'infsh login' (implying API credentials) yet the skill metadata declares no required environment variables or credentials — a mismatch between claimed requirements and runtime instructions.

Instruction Scope

Runtime instructions tell the agent/user to download and run an external installer (curl https://cli.inference.sh | sh) and to run 'infsh login' and 'infsh app run' to send prompts/images to a remote inference service. The instructions remain within the design task, but they direct network installation and remote execution and will transmit generated image prompts and likely outputs to an external service; the SKILL.md does not document what data is sent, retained, or how authentication is handled.

Install Mechanism

There is no formal install spec in the package, and the SKILL.md recommends piping a remote installer script into sh (curl | sh). Even though the doc claims the installer verifies SHA-256 checksums from dist.inference.sh, piping a remote script is high-risk unless the user inspects it; the registry metadata does not enforce or declare a vetted install mechanism.

Credentials

Declared requirements list no environment variables or primary credential, but the instructions call for 'infsh login' which implies API credentials or interactive auth. The absence of any declared credential requirements is an under-specification that could hide credential prompts or token usage; no guidance is provided on where credentials are stored or what scopes the token has.

Persistence & Privilege

The skill is instruction-only, does not request always-on presence, and does not modify other skills or request system-wide config. It does ask the user to install a third-party CLI, but the skill itself does not demand elevated platform privileges.

What to consider before installing

This skill appears to do what it says (help make book covers) but has a few red flags you should consider before installing: (1) The README tells you to run a remote installer via 'curl | sh' — avoid piping unknown scripts; download the installer manually and inspect it, or fetch the binary directly and verify the SHA-256 checksums yourself. (2) The instructions call for 'infsh login' but the skill metadata lists no required credentials — expect to provide an API key/account; ask the author what credentials are needed, how they are stored, and what permissions/tokens are used. (3) Using the external CLI will send prompts and generated images to a third-party service — check the service's privacy, retention, and copyright policy before sending any sensitive or unpublished manuscript content. (4) If you prefer more control, use a locally installed or self-hosted image model, or require the skill to declare its credential requirements and provide a non-network install option. If you proceed, manually review the installer and the service's terms and verify checksum URLs before running any remote script.

Create genre-appropriate book covers with AI image generation via inference.sh CLI.

Quick Start

curl -fsSL https://cli.inference.sh | sh && infsh login

# Generate a thriller cover concept
infsh app run falai/flux-dev-lora --input '{
  "prompt": "dark moody book cover art, lone figure standing at end of a rain-soaked alley, dramatic chiaroscuro lighting, noir atmosphere, cinematic, high contrast shadows",
  "width": 832,
  "height": 1248
}'

Install note: The install script only detects your OS/architecture, downloads the matching binary from dist.inference.sh, and verifies its SHA-256 checksum. No elevated permissions or background processes. Manual install & verification available.

Genre Conventions

Readers judge books by covers. Matching genre expectations is critical — a romance reader will skip a cover that looks like sci-fi, regardless of content.

Fiction

Genre	Palette	Imagery	Typography	Mood
Thriller/Mystery	Dark (black, navy, blood red)	Lone figure, urban scenes, shadows	Bold sans-serif, all caps	Tense, ominous
Romance	Warm (pink, red, gold, soft purple)	Couples, flowers, scenic backdrops	Script/cursive, elegant serif	Passionate, dreamy
Sci-Fi	Cool (blue, teal, purple, silver)	Space, tech, geometric shapes	Clean sans-serif, futuristic	Vast, technological
Fantasy	Rich saturated (emerald, crimson, gold)	Swords, magic, landscapes, creatures	Decorative serif, ornamental	Epic, magical
Literary Fiction	Muted, sophisticated	Abstract, minimal, symbolic	Elegant serif, understated	Thoughtful, artistic
Horror	Dark with high contrast pops	Faces, shadows, isolation, decay	Distressed, bold, dripping	Dread, unease
Historical	Sepia, muted period-accurate	Period clothing, architecture, artifacts	Classical serif	Nostalgic, authentic

Non-Fiction

Category	Style	Imagery	Typography
Business/Self-help	Clean, bold, 2-3 colors	Minimal or none, icon optional	Large bold sans-serif title
Memoir	Personal, warm	Author photo or atmospheric scene	Mix of serif and sans
Science/Academic	Professional, structured	Diagrams, abstract visuals	Clean serif, structured layout
Cookbook	Appetizing, bright	Hero food photograph	Warm, inviting fonts
Travel	Vibrant, aspirational	Destination photography	Adventure-style fonts

Cover Sizing

Print (Trim Sizes)

Format	Dimensions	Common For
Mass market paperback	4.25 x 6.87"	Genre fiction
Trade paperback	5.5 x 8.5"	Most fiction/non-fiction
Standard	6 x 9"	Non-fiction, textbooks
Large format	7 x 10"	Coffee table, art books

Digital

Platform	Cover Size	Aspect Ratio
Amazon Kindle	2560 x 1600 px (min 1000 x 625)	1.6:1
Apple Books	1400 x 1873 px minimum	~3:4
General ebook	2500 x 3750 px	2:3

Spine Width

Approximate: page count / 400 = spine width in inches (varies by paper stock).

• 200 pages ≈ 0.5" spine
• 400 pages ≈ 1.0" spine

Layout Zones

┌─────────────────────────┐
│     TITLE ZONE          │ ← Top 1/3: Title must be readable here
│     (largest text)      │    This is what shows in thumbnails
│                         │
│                         │
│     MAIN IMAGE          │ ← Middle: Core visual/illustration
│     ZONE                │    The emotional hook
│                         │
│                         │
│     SUBTITLE /          │ ← Bottom area: Author name, subtitle
│     AUTHOR ZONE         │    Smaller text, less critical at thumbnail
└─────────────────────────┘

The Thumbnail Test

Your cover will be seen at 80x120px on Amazon, 60x90px in search results, and ~40x60px on mobile grids.

At thumbnail size, readers must be able to identify:

1. The genre (from color and composition)
2. The title (if large enough)
3. The mood (from imagery)

Test: shrink your cover to 80px wide. If you can't read the title or identify the genre, redesign.

Prompting by Genre

Thriller

infsh app run falai/flux-dev-lora --input '{
  "prompt": "dark cinematic book cover scene, silhouette of a person standing before a foggy bridge at night, single streetlamp casting long shadows, noir atmosphere, high contrast, desaturated blue tint, dramatic tension",
  "width": 832,
  "height": 1248
}'

Romance

infsh app run bytedance/seedream-4-5 --input '{
  "prompt": "romantic soft-focus scene, couple silhouetted against golden sunset on a beach, warm pink and gold tones, bokeh lights, dreamy atmosphere, soft pastel sky, intimate mood",
  "size": "2K"
}'

Sci-Fi

infsh app run falai/flux-dev-lora --input '{
  "prompt": "science fiction book cover art, massive space station orbiting a ringed planet, deep blue and teal color palette, stars and nebula background, hard sci-fi aesthetic, cinematic scale, clean geometric architecture",
  "width": 832,
  "height": 1248
}'

Fantasy

infsh app run xai/grok-imagine-image-pro --input '{
  "prompt": "epic fantasy book cover illustration, ancient stone castle on a cliff overlooking a misty valley, magical aurora in the sky, rich emerald and gold colors, detailed environment, sense of wonder and adventure",
  "aspect_ratio": "2:3"
}'

Non-Fiction / Business

infsh app run falai/flux-dev-lora --input '{
  "prompt": "minimal abstract book cover background, clean gradient from deep navy to white, subtle geometric pattern, professional and modern, negative space, corporate aesthetic",
  "width": 832,
  "height": 1248
}'

Typography Rules

AI cannot render text reliably. Generate the cover art/background with AI, then add typography in a design tool.

Title Hierarchy

1. Title — largest, most prominent, top 1/3 of cover
2. Subtitle — smaller, below title or at bottom
3. Author name — bottom of cover, size depends on author recognition

Font Pairing by Genre

• Thriller: bold sans-serif title + condensed sans-serif author
• Romance: script/cursive title + elegant serif author
• Sci-Fi: geometric sans-serif for both
• Fantasy: decorative/medieval serif title + clean serif author
• Business: heavy bold sans-serif title + light sans-serif subtitle

Iteration Workflow

# 1. Generate 5+ concepts across different models
infsh app run falai/flux-dev-lora --input '{"prompt": "...", "width": 832, "height": 1248}' --no-wait
infsh app run bytedance/seedream-4-5 --input '{"prompt": "..."}' --no-wait
infsh app run xai/grok-imagine-image-pro --input '{"prompt": "...", "aspect_ratio": "2:3"}' --no-wait

# 2. Refine best concept with image-to-image editing
infsh app run bytedance/seededit-3-0-i2i --input '{
  "prompt": "make the sky more dramatic with storm clouds, increase contrast",
  "image": "path/to/best-concept.png"
}'

# 3. Upscale for print quality
infsh app run falai/topaz-image-upscaler --input '{
  "image": "path/to/final-cover.png",
  "scale": 4
}'

Common Mistakes

Mistake	Problem	Fix
Wrong genre signals	Readers skip it	Study bestsellers in your genre
Title too small	Invisible at thumbnail	Title should fill top 1/3
Too much detail	Muddy at small sizes	Simplify, use negative space
AI-generated text	Garbled letters	Add text in design tool
Centered everything	Static, boring	Use asymmetry intentionally
Following trends blindly	Dates quickly	Classic genre conventions endure

Checklist

• Genre instantly recognizable from colors and composition
• Title readable at 80px wide (thumbnail test)
• No AI-generated text on cover
• Works in both color and greyscale
• Correct dimensions for target platform
• Author name visible but not competing with title
• High resolution (300 DPI for print, 2500px+ for digital)
• Spine text readable (for print)

Related Skills

npx skills add inference-sh/skills@ai-image-generation
npx skills add inference-sh/skills@prompt-engineering
npx skills add inference-sh/skills@image-upscaling

Browse all apps: infsh app list