Agent skill
book-cover-design
Book cover design with genre-specific conventions, typography rules, and AI image generation. Covers fiction and non-fiction genres, sizing, thumbnail testing, and iteration workflows. Use for: self-publishing, ebook covers, print covers, audiobook covers, cover mockups. Triggers: book cover, cover design, ebook cover, book art, novel cover, self publishing cover, kindle cover, audiobook cover, book jacket, cover illustration, fiction cover, nonfiction cover
Install this agent skill to your Project
npx add-skill https://github.com/inference-sh/skills/tree/main/guides/design/book-cover-design
SKILL.md
Book Cover Design
Create genre-appropriate book covers with AI image generation via inference.sh CLI.
Quick Start
Requires inference.sh CLI (
infsh). Install instructions
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
}'
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:
- The genre (from color and composition)
- The title (if large enough)
- 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
- Title — largest, most prominent, top 1/3 of cover
- Subtitle — smaller, below title or at bottom
- 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
Recommended Agent Skills
Expand your agent's capabilities with these related and highly-rated skills.
agent-ui
Batteries-included agent component for React/Next.js from ui.inference.sh. One component with runtime, tools, streaming, approvals, and widgets built in. Capabilities: drop-in agent, human-in-the-loop, client-side tools, form filling. Use for: building AI chat interfaces, agentic UIs, SaaS copilots, assistants. Triggers: agent component, agent ui, chat agent, shadcn agent, react agent, agentic ui, ai assistant ui, copilot ui, inference ui, human in the loop
chat-ui
Chat UI building blocks for React/Next.js from ui.inference.sh. Components: container, messages, input, typing indicators, avatars. Capabilities: chat interfaces, message lists, input handling, streaming. Use for: building custom chat UIs, messaging interfaces, AI assistants. Triggers: chat ui, chat component, message list, chat input, shadcn chat, react chat, chat interface, messaging ui, conversation ui, chat building blocks
tools-ui
Tool lifecycle UI components for React/Next.js from ui.inference.sh. Display tool calls: pending, progress, approval required, results. Capabilities: tool status, progress indicators, approval flows, results display. Use for: showing agent tool calls, human-in-the-loop approvals, tool output. Triggers: tool ui, tool calls, tool status, tool approval, tool results, agent tools, mcp tools ui, function calling ui, tool lifecycle, tool pending
widgets-ui
Declarative UI widgets from JSON for React/Next.js from ui.inference.sh. Render rich interactive UIs from structured agent responses. Capabilities: forms, buttons, cards, layouts, inputs, selects, checkboxes. Use for: agent-generated UIs, dynamic forms, data display, interactive cards. Triggers: widgets, declarative ui, json ui, widget renderer, agent widgets, dynamic ui, form widgets, card widgets, shadcn widgets, structured output ui
web-search
Web search and content extraction with Tavily and Exa via inference.sh CLI. Apps: Tavily Search, Tavily Extract, Exa Search, Exa Answer, Exa Extract. Capabilities: AI-powered search, content extraction, direct answers, research. Use for: research, RAG pipelines, fact-checking, content aggregation, agents. Triggers: web search, tavily, exa, search api, content extraction, research, internet search, ai search, search assistant, web scraping, rag, perplexity alternative
ai-rag-pipeline
Build RAG (Retrieval Augmented Generation) pipelines with web search and LLMs. Tools: Tavily Search, Exa Search, Exa Answer, Claude, GPT-4, Gemini via OpenRouter. Capabilities: research, fact-checking, grounded responses, knowledge retrieval. Use for: AI agents, research assistants, fact-checkers, knowledge bases. Triggers: rag, retrieval augmented generation, grounded ai, search and answer, research agent, fact checking, knowledge retrieval, ai research, search + llm, web grounded, perplexity alternative, ai with sources, citation, research pipeline
Didn't find tool you were looking for?