Engine is the AI model that draws your images. The choices are:
- GPT Image 2.5 Sunburst (default)
- Nano Banana Pro
- Nano Banana 2
Each engine also has a Quality setting.
Sizes
- Collage size: 1K or 2K.
- Final size: 1K, 2K or 4K.
- A 3×3 contact sheet is always 4K.
Tip: 2K is enough for most online stores. Choose 4K if you need to zoom in a lot or print. Bigger sizes cost more credits; the Estimate panel shows the difference before you start.