Nano Banana Prompt

Nano Banana Prompt Generator

Overview

Nano Banana is Google's autoregressive image generation model (also known as Gemini 2.5 Flash Image, and the Pro version as Gemini 3 Pro Image). This skill generates optimized prompts that leverage Nano Banana's unique capabilities: strong prompt adherence, character consistency, and nuanced control through structured formatting.

Core Prompting Formula

Every Nano Banana prompt follows this structure:

Subject + Action + Environment + Art Style + Lighting + Details

Key Techniques

1. Use Markdown Formatting

Structure prompts with headers, bullet points, and sections. Nano Banana's text encoder parses markdown effectively.

# Subject
[Main focus description]

## Core Design
- Detail 1
- Detail 2

## Environment
[Background/setting]

2. Capitalize Enforcement Keywords

Use ALL CAPS for critical requirements:

• MUST - Mandatory elements
• DO NOT - Forbidden elements
• ONLY - Exclusive requirements

Example: "The composition MUST use portrait orientation"

3. Specify Technical Parameters

Include camera and composition specifications:

4. Layer Lighting Sources

Specify multiple light sources for depth:

## Lighting
- Primary: [Main light source and direction]
- Secondary: [Fill light or ambient]
- Accent: [Rim light, highlights, glows]

5. Use Prestige Anchoring

Reference acclaimed artists or prestigious descriptors to improve quality:

6. Include Negative Constraints

Always add a "Do NOT Include" section:

## Do NOT Include
- Text, watermarks, or logos
- Modern anachronistic elements
- [Style-specific exclusions]

Prompt Template

Use this template structure for all Nano Banana prompts:

# [Title/Subject Name]

## Format Specifications
- **Orientation**: [Portrait/Landscape/Square] ([aspect ratio])
- **Color**: [Full color / Black and white / Limited palette]
- **Purpose**: [Book illustration / Concept art / Character design]

## Subject
[Detailed description of the main focus]

## Core Design
- [Key visual element 1]
- [Key visual element 2]
- [Key visual element 3]

## Critical Details (MUST include)
- [Non-negotiable element 1]
- [Non-negotiable element 2]

## Environment
[Setting, background, atmospheric details]

## Art Style
[Specific aesthetic, artist references, medium]

## Lighting
- Primary: [Main light]
- Secondary: [Fill/ambient]
- Accent: [Highlights/glows]

## Composition
[Rule of thirds, framing, focal points, camera specs]

## Atmosphere/Mood
[Emotional tone, narrative context]

## Technical Specifications
[Print quality, detail density, rendering style]

## Do NOT Include
- [Exclusion 1]
- [Exclusion 2]
- [Exclusion 3]

Workflow

Step 1: Gather Parameters

Collect from user or determine from context:

Step 2: Analyze Source Material

When generating prompts from written descriptions (scenes, chapters, etc.):

1. Identify the most visually dynamic moment
2. Extract specific physical details (colors, materials, scale)
3. Note environmental context
4. Capture emotional/atmospheric tone
5. Identify any unique or fantastical elements requiring special attention

Step 3: Structure the Prompt

Build the prompt using the template, ensuring:

1. Subject section clearly establishes the main focus
2. Core Design breaks down visual components systematically
3. MUST/DO NOT sections enforce critical requirements
4. Art Style anchors to recognizable aesthetics
5. Lighting creates depth with multiple sources
6. Composition specifies camera and framing

Step 4: Validate and Refine

Check the prompt against these criteria:

Special Formats

Black and White Illustration

Add these specifications:

## Format Specifications
- **Color**: BLACK AND WHITE ONLY—high contrast monochromatic, no color

## Art Style
- High contrast black and white ink illustration
- Style: [Artist reference] (e.g., Bernie Wrightson, Frank Miller)
- Heavy blacks for shadows
- Pure whites for highlights
- Crosshatching for texture and gradation

Character Design Sheet

Add these specifications:

## Format Specifications
- **Purpose**: Character design reference sheet
- **Views**: Front, 3/4, profile (or specify which)

## Character Details
- Height/build reference
- Distinctive features
- Costume/clothing breakdown
- Color callouts (if color)
- Expression range (if multiple expressions)

Action Scenes

Add motion indicators:

## Motion and Energy
- Speed lines style: [Classic illustration / manga / subtle blur]
- Motion direction: [Left-to-right / diagonal / toward camera]
- Dynamic elements: [Hair, clothing, debris, particles]
- Frozen moment: [Describe the exact instant captured]

Quality Standards

Every generated prompt must:

1. Use Markdown Structure - Headers, bullets, clear sections
2. Include Format Specs - Orientation, color mode, purpose
3. Specify Subject Clearly - Main focus with physical details
4. Enforce Critical Elements - MUST/DO NOT sections present
5. Anchor Style - Artist reference or prestige descriptor
6. Layer Lighting - At least 2 light sources described
7. Define Composition - Camera, framing, focal point
8. Exclude Unwanted Elements - Clear DO NOT section

Example Usage

User: "Create a prompt for a dragon attacking a castle at sunset"

Response approach:

1. Determine format (likely landscape for epic scene)
2. Establish subject (dragon as focus, castle as environment)
3. Select style anchors (fantasy art references)
4. Specify dramatic sunset lighting (golden hour + fire)
5. Add motion for attack (wings, fire breath, debris)
6. Exclude common unwanted elements (text, watermarks)
7. Structure using full template

References

For additional guidance on Nano Banana capabilities, consult:

• Max Woolf's Nano Banana Prompting Guide
• Google's Nano Banana Pro Prompting Tips

Editing Images (Nano Banana Pro)

When editing existing images rather than generating new ones, use these five action words: