Guide · Image models for e-commerce

Nano Banana vs ChatGPT Image for product ads: which to use

Q: Is Nano Banana or ChatGPT Image better for product photos?

In our tests Google Nano Banana gave the most realistic product photography: material texture, true colour and natural light. Use it for any image with no text, such as an Amazon main image, lifestyle photos, macro details and flat lays.

Q: Which AI image model is best for posters and infographics with text?

ChatGPT Image. It renders headlines, labels, dimensions and structured layouts reliably. Nano Banana often misspells or distorts text, and a single bad word spoils the whole poster, so send any image with text to ChatGPT Image.

Q: Why does ChatGPT Image add strokes, slanted text and clutter?

When the prompt leaves type and decoration open, it fills the gaps with its own habits: outlined or stroked letters, italic or tilted headlines, extra lines, badges and shadows. Spell out the font style, sizes, weights, alignment and margins, and say plainly that text is horizontal with no strokes, outlines, shadows or extra elements.

Short answer from our tests: no text in the image → Google Nano Banana. Any text in the image → ChatGPT Image. Nano Banana makes the most realistic product photos, but one misspelled or warped word ruins a poster. ChatGPT Image gets the text and layout right, but its photos look less real and it adds its own decoration unless the prompt sets strict design rules.

Observations from one product tested across 20+ images (the set in our Amazon & Shopify listing guide and Shopify store guide). Models change often. Treat this as a starting rule, not a ranking. We make Poster Grammar, which lets you use both.

The rule

	Google Nano Banana (Gemini image models)	ChatGPT Image
Best at	Realistic photos: material texture, true colour, natural light, believable scenes	Text, headlines, labels, measurements, infographics, structured layouts
Weak at	Any text: misspellings, warped letters, invented words	Photo realism. Without rules it adds strokes, slanted text and clutter
Use for	Amazon main image, Shopify gallery and hero banners, lifestyle, macro, flat lay	Amazon and Shopify size, feature, comparison and trust images; posters; ads with copy
Prompt tip	Say "no text" and leave space empty for text added later	Give exact type and design rules (below)

Photo-only hero made with Nano Banana — No text → Nano Banana

Feature infographic made with ChatGPT Image — Text → ChatGPT Image

Need both? Make the photo with Nano Banana and leave the text area empty. Then attach that photo to ChatGPT Image and ask it to add only the listed text, without changing the photo. Or add the text yourself in an editor.

The design rules ChatGPT Image needs

Left alone, ChatGPT Image decorates: outlined or stroked letters, italic or tilted headlines, extra lines and badges, shadows, cramped edges. It follows instructions well, so tell it exactly what the type looks like. Paste this block into any prompt with text and change the values:

Type and design rules block

TYPE AND DESIGN RULES (follow exactly):
- Headline: bold geometric sans-serif, all caps, about 90 px tall on a 2000 px canvas, colour #3F4A2E, at most 2 lines, left-aligned.
- Labels: same typeface, bold, about 42 px. Body lines: regular weight, about 30 px, line height 1.3.
- One typeface family only. Clear size steps: headline at least twice the label size.
- Every line of text perfectly horizontal on a straight baseline. No italic, slanted, rotated, curved or warped text.
- No outlines, strokes, glows, drop shadows, bevels or 3D effects on text or icons.
- Icons: simple single-weight line icons, all the same size and stroke.
- Only the text listed in this prompt, spelled exactly. No extra words, numbers, badges, stars, seals or logos.
- At least 120 px clear margin on every side; nothing touches the edges. Equal spacing between repeated rows.
- Flat background: no textures, patterns or decorative shapes beyond those described.

Why each line is there

Sizes in pixels stop it from shrinking text to fit, or blowing it up.
"Horizontal, no italic" stops the tilted "dynamic" headline it likes to add.
"No outlines or strokes" stops the outlined and double-stroked letters.
"Only the text listed" stops invented badges, fake ratings and extra words.
Margins stop text from touching the edges, where it gets cropped on phones.

Rules for Nano Banana photos

Attach a photo of the real product and say to keep its shape, logo, colours and printed text exactly.
Describe the light as the camera sees it ("soft highlight down the left edge, gentle shadow to the right"). If you name lighting gear, the model may draw it in the picture.
End with "no text, no badges, no extra products" so nothing turns up that you'd need to fix.
For banners, say which part of the frame stays empty for live text.

Questions

Is Nano Banana or ChatGPT Image better for product photos?

In our tests, Nano Banana gave the most realistic product photography. Use it for any image without text.

Which AI image model is best for posters and infographics with text?

ChatGPT Image. It renders headlines and labels reliably. Nano Banana often warps text, and one bad word spoils the poster.

Why does ChatGPT Image add strokes, slanted text and clutter?

Because the prompt leaves type and decoration open. Give it the rules block above: font style, sizes, weights, alignment, margins, and no strokes, slants or extras.