Gumroad thumbnail size: 600 x 600 and cover dimensions

Workflow

• Separate cover and thumbnail
• Write a factual brief
• Constrain the prompt
• Generate real variants
• Run visual QA
• Publish the set deliberately

1. Design for two different jobs

Gumroad treats cover images and thumbnails as separate assets. Its current help page recommends a cover at least 1280×720 pixels and a thumbnail at least 600×600. The cover sells the offer on the product page. The thumbnail has to remain recognizable in a profile, library, or discovery grid.

Keep the typography, palette, and visual metaphor related so the two assets look like one product. Recompose rather than crop: a center crop can cut the product name, price, device frame, or focal object.

2. Turn the offer into a factual image brief

An image model does not need the whole sales page. It needs the product identity and the few facts that should control the composition.

If the product has no real interface, do not request a realistic screenshot and then publish the invented UI as evidence. Use an abstract composition, a document or template metaphor, or label the mockup clearly as illustrative.

3. Constrain the prompt around hierarchy

OpenAI's current GPT Image prompting guide recommends explicit composition, typography, color, and constraints. State what must dominate, where the eye should travel, and which failure modes to avoid.

Create a polished 1280x720 digital-product cover.

Exact product name: "Client Portal Kit"
Audience and outcome: Freelancers who need a consistent client-onboarding system.
Style: Premium minimalist editorial layout.
Palette: #111827, #06B6D4, #F8FAFC.

Composition:
- Product name is the largest element and remains readable at small size.
- Use one clear focal object and generous negative space.
- Include no text except the exact product name.
- Do not invent logos, testimonials, awards, prices, or product features.
- Avoid tiny UI labels, watermarks, clutter, and low-contrast type.

Return one finished storefront cover, not a collage.

For a square thumbnail, change the canvas, enlarge the title, reduce the number of objects, and ask for a composition that remains identifiable at roughly 150 pixels wide.

4. Generate different compositions, not cosmetic reruns

Three options are useful only when they test different visual decisions. Hold the facts, spelling, palette, and size constant, then vary the composition deliberately.

• Option one: centered title with one strong focal object.
• Option two: asymmetric title and image balance with more movement.
• Option three: editorial or premium layout with deeper layering and quieter detail.

Do not change the product promise between options. You are comparing designs, not allowing the image model to rewrite the offer. Use a lower quality setting for exploratory drafts when cost or speed matters, then regenerate the selected direction at the intended final quality.

5. Review at full size and grid size

Run two passes. Full size exposes generation defects; small size reveals whether the hierarchy survives the real storefront placement.

If the title is almost right, do not publish it. Regenerate or replace the typography in a design editor. A near-miss is still a storefront typo.

6. Publish the set deliberately

Gumroad currently allows multiple cover or preview files and recommends equal heights when you use more than one. Make the first cover the clearest expression of the offer, then use later panels for real screenshots, included assets, before-and-after context, or a concise benefit breakdown.

1. Upload the reviewed landscape cover.
2. Upload the separately composed square thumbnail.
3. If using multiple covers, keep their heights and visual system consistent.
4. Preview the product page and profile/grid placement.
5. Check mobile, spelling, price, and crop one final time.
6. Keep the rejected variants out of the live set unless each contributes new buyer information.

Make the three-option pass repeatable

Common questions