Anapoly AI Labs

Banana Nano Pro Prompt Generator

Source material created by Dylan Davis and made freely available through his YouTube channel. Accessed: 17 December 2025

Transparency label: AI-generated

Objective: To consistently generate professional-grade image prompts for Nano Banana Pro by outsourcing the technical prompting to a custom AI “Gem”.

Role: The User acts as the “Creative Director” (providing intent), while the Gem acts as the “Technical Prompter” (formatting for the model).

Tools Required

  • Google Gemini Advanced (to create and use Gems)
  • Nano Banana Pro (Image Generation Model)
  • Reference Images (Optional but recommended)

Phase 1: One-Time Setup (Creating the Gem)

Note: This step only needs to be done once to build the tool.

  1. Create a New Gem: Open Gemini and start a new Gem (custom AI assistant).
  2. Define the Instructions: In the instructions section for the Gem, paste the content of file 2025-12-16_Prompt_Base-Prompt-for-Nano-Banana-Pro-Prompt. The file contains directives that cover the following logic derived from the source:
    • Role Definition: You are an expert at prompting the Nano Banana Pro image model.
    • Task: Your job is to take five specific user inputs and synthesize them into high-quality image prompts.
    • Input Guardrails: If the user does not provide all five inputs (Purpose, Audience, Subject, Brand Rules, Reference Image), ask them to provide the missing information before generating prompts.
    • Output Styles: Generate three distinct prompt variations:
      • Literal
      • Creative
      • Premium
    • Output Format: The final output must be in JSON format (using labels and descriptions within brackets). This structure resonates most effectively with Nano Banana Pro.
    • Research Logic: Use internal reasoning to infer aspect ratios and styles based on the “Purpose” provided (e.g., if the purpose is “Instagram,” infer a vertical aspect ratio).

Phase 2: Input Data (The 5-Step Context)

When you are ready to generate an image, open your custom Gem and provide the following five inputs. You do not need to worry about technical jargon; just use natural language.

  1. Purpose: Why are you creating this image?
    • Examples: Instagram ad, YouTube thumbnail, Pitch deck, Landing page hero section.
    • Why: This dictates aspect ratio and composition.
  2. Audience: Who is this image for?
    • Examples: Luxury buyers, Tech executives, Gen Z consumers.
  3. Subject: What is the primary focus?
    • Examples: A matte black ceramic mug, a specific person, a character.
  4. Brand Rules: What are the aesthetic guidelines?
    • Examples: Warm tones, minimal styling, specific brand colors, or fonts.
  5. Reference Image (Yes/No): Are you providing a reference image to the image model?
    • Context: Mention if you are inserting a product into a scene, using a sketch, or mimicking a competitor’s ad composition.

Phase 3: Generation & Execution

  1. Run the Gem: Submit the five inputs. The Gem will “think” (reason) and output three blocks of code (Prompts A, B, and C) in JSON format.
  2. Copy the Prompt: Select “Copy Code” on the variation you prefer (e.g., Prompt A).
  3. Paste into Nano Banana Pro: Paste the copied JSON prompt into the Nano Banana Pro input field.
  4. Upload Reference Image: If you specified a reference image in Phase 2 (e.g., a photo of your product), upload it now. Nano Banana Pro excels at taking existing references and inserting them into new scenes.
  5. Generate: Run the model to produce the initial images.

Phase 4: Refinement & Editing

Do not start from scratch if the image is close to perfect. Nano Banana Pro allows for high-quality minor edits without re-rolling the prompt.

  1. Analyze the Result: If the image is 90% there but needs tweaks (e.g., background is wrong, text is misplaced), keep the image open.
  2. Conversational Edits: Type instructions like a creative director to adjust specific elements.
    • Example: “Make the background warmer,” “Move the text to the left,” or “Zoom out and place this mug in a coffee shop”.
  3. Final Polish (Watermarks): If the model leaves a watermark:
    • Download the image.
    • Upload it to a tool like Canva.
    • Use the “Magic Eraser” tool to remove the watermark.

Summary checklist for every run:

  • Did I provide all 5 inputs (Purpose, Audience, Subject, Brand, Reference)?
  • Did I copy the JSON output?
  • Did I attach my reference image in Nano Banana Pro?
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