How to Fix Broken Hands in Nano Banana 2 Portraits with Image-to-Image

When generating character art, the most common frustration remains the occasional distortion of human anatomy, particularly hands. Fingers may merge, palms might appear extra-large, or wrists can look disconnected from the rest of the body. These artifacts are a known limitation in many generative models, but they do not have to ruin your final composition. This guide explains how to address these issues specifically within Nano Banana 2 using its image-to-image workflow.

It is important to clarify that Nano Banana refers to the AI image generation and editing tool itself. It is not a skincare brand, bottle, jar, or physical subject. Understanding this distinction ensures you focus on the digital capabilities of the software rather than expecting physical product attributes. The goal here is to apply specific prompt instructions to correct visual errors without altering the core identity of your character.

Diagnosing the Symptom: Why Hands Break

The symptom of broken hands usually manifests as anatomical impossibilities. You might see six fingers, missing knuckles, or hands that blend into clothing or background elements. In the context of AI generation, these errors often stem from the model struggling to understand complex spatial relationships between joints and digits. While the underlying technology processes vast amounts of data, it does not inherently possess a perfect understanding of human biology in every generated instance.

Separating plausible causes from known facts is essential for troubleshooting. A plausible cause might be a vague prompt that fails to emphasize hand structure. However, a known fact is that even with detailed prompts, certain models struggle with fine details like fingers. Google documents Nano Banana 2 as Gemini 3.1 Flash Image (gemini-3.1-flash-image), which is distinct from other versions like Nano Banana Pro or Nano Banana 2 Lite. Each model has different strengths; for instance, Nano Banana 2 Lite is focused on speed and cost and is not optimized for multiple reference inputs or multi-turn sequential editing. Therefore, relying on the Lite version for complex anatomical corrections without understanding its limitations could lead to further degradation of the image quality.

Applying Targeted Prompt Instructions

To fix these issues, you must leverage the prompt library available within Nano Banana 2. The platform supports text-to-image and image-to-image workflows, allowing you to upload an existing portrait and refine it. When using image-to-image mode, the system uses your uploaded image as a base while interpreting new text instructions to modify specific areas.

Prompt instructions describe desired outcomes; they do not guarantee identity, label, object, or typography preservation. This means that while you can ask for better hands, the overall style or facial features might shift slightly. To address broken hands, you should construct a prompt that explicitly requests anatomical correction. For example, you might use a directive such as "correct hand anatomy, ensure five distinct fingers per hand, and fix palm proportions."

These examples are untested prompt suggestions intended to illustrate the syntax required. They serve as a starting point for your own experimentation. When entering these instructions, ensure you are working within the main Nano Banana 2 interface, which corresponds to the Gemini 3.1 Flash Image model. Avoid using the Lite version if you require high-fidelity anatomical adjustments, as it lacks the optimization for complex edits found in the standard Nano Banana 2 environment.

Verifying the Correction and Next Steps

After submitting your request, review the generated output carefully. Look for the specific improvements: count the fingers, check the wrist connection, and ensure the palm size looks natural relative to the arm. If the result is still imperfect, you may need to iterate. Since Nano Banana 2 supports iterative refinement, you can upload the corrected image again with adjusted phrasing in your prompt. However, remember that repeated iterations can sometimes introduce new artifacts or drift from the original character design.

If you find that the standard workflow does not yield the desired results, consider exploring the broader capabilities of the platform. For users requiring advanced features or higher fidelity, the Nano Banana Pro page at /nanobananapro offers access to the Gemini 3 Pro Image model. Conversely, the website has a Nano Banana Lite page at /nanobananalite, but this does not by itself establish support for all Google Nano Banana 2 Lite features. Always verify the specific model capabilities before assuming a feature is available.

For those ready to attempt these fixes immediately, you can start the process right away. Try Nano Banana to access the image-to-image tools and begin refining your character portraits. By combining clear prompt instructions with the appropriate model selection, you can significantly reduce the frequency of broken hands and achieve more professional-looking AI art.

Remember that while these methods improve success rates, no AI tool guarantees perfect outcomes in every single generation. Continuous practice and prompt tuning remain the best strategies for mastering the craft of AI image editing.