Here's a comprehensive summary of tips for getting Nano Banana (Gemini) to generate images better suited for small use cases:
Use specific dimension keywords:
- "32×32 pixel art icon of [subject]"
- "16-bit pixelated [subject]"
- "8-bit pixel art in the style of [retro game]"
- "Low-resolution pixel art" or "chunky pixels"
Caution with Nano Banana Pro: The Pro version has a bias toward realism and may push pixel art toward 32-bit quality rather than true 8-bit styles. The base Nano Banana (Gemini 2.5 Flash Image) may work better for intentionally stylized looks.
Effective prompt formula:
An icon representing a [subject]. The background is white.
Make the icon in a colorful and tactile 3D style. No text.
For Discord/profile avatars:
Create a [style] avatar image to represent [subject/character].
Centered composition, clean edges.
The problem: Nano Banana doesn't output true alpha transparency. Asking for "transparent background" produces white, black, or fake checkerboard patterns.
Best workaround - Black/White difference method:
- Generate your asset on a pure white (#FFFFFF) background
- Feed it back asking to change the white to pure black (#000000)
- Use math to calculate transparency from the pixel differences
- This preserves semi-transparent effects like glass and shadows
Alternative - Chromakey green method:
[Your subject] on a solid, flat, uniform chromakey green background
using EXACTLY hex color #00FF00. The subject MUST have a clean white
outline/border (2-3 pixels wide) separating it from the green background.
Crisp, sharp, well-defined edges - no soft or blurry boundaries.
Then strip the green using HSV detection in post-processing.
- Don't over-prompt: Skip "4k, trending on artstation, masterpiece" spam. Natural language works better.
- Describe scenes, don't list keywords: A narrative paragraph beats disconnected words.
- Use photographic language: "macro shot", "low-angle perspective", "85mm portrait lens"
- For text: "Write the text 'HELLO' in a bold, red, serif font on the sign"
- Sticker style: "A cartoon/illustration sticker style with bold colors, clean white outline"