AI tattoo generator: design ideas and a preview on your skin

To use an AI tattoo generator, ask for the design as clean black linework on a plain white background, the look of a flash sheet, and compare a few versions. To see a design on your body, send a photo of the spot and the design to an image model together and describe the placement and size. Then take the design to a tattoo artist to redraw for your skin. On Sume, ChatGPT Image 2.5 today returns up to 4 designs per call and takes up to 16 reference images, so the photo and the design fit in one request.

Sume facts come from the Image API docs and the request schemas in the Sume API reference, read on 2026-09-28.

How do I write a tattoo design prompt?

Describe the design the way you would to an artist, and send it to POST /v1/images with openai/gpt-image-2.5:

• The subject and style: "a fine-line peony with two leaves", "a traditional swallow with bold outlines", or "a geometric wolf head".
• The flash-sheet look: "black linework on a plain white background, no shading", or "with dotwork shading".
• The shape of the spot: a long vertical design for a forearm, a small round one for a wrist. Match aspect_ratio to it, such as 9:16 or 1:1.
• n for up to 4 versions per call. Each completed image is billed.

curl -X POST "https://api.sume.com/v1/images" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-image-2.5",
    "prompt": "Tattoo design: a fine-line peony with two leaves, drawn as a long vertical piece for a forearm. Black linework on a plain white background, no shading, no text.",
    "aspect_ratio": "9:16",
    "n": 4
  }'

How do I see a tattoo design on my body?

Take a well-lit photo of the spot, put it and the design at public HTTPS URLs, and send both in input_references. It is the same two-image request as an AI mockup: the prompt names each image by what it shows, and aspect_ratio is set to your photo's shape, such as 3:4, rather than "auto". Then give the placement, the size, and what must stay.

{
  "model": "openai/gpt-image-2.5",
  "prompt": "Place the peony from the line drawing on the inner forearm in the arm photo, about a hand's length tall, as black ink following the curve of the arm. Keep the arm, the skin, and the background as they are.",
  "input_references": [
    { "type": "image_url", "image_url": { "url": "https://example.com/forearm.jpg" } },
    { "type": "image_url", "image_url": { "url": "https://example.com/peony-lines.png" } }
  ],
  "aspect_ratio": "3:4",
  "n": 4
}

Can I turn a photo into a tattoo design?

Yes. Send the photo, such as a pet, a flower, or a skyline, as the only reference and ask for "black linework on white, simplified for a tattoo". With one reference, aspect_ratio: "auto" keeps the photo's shape.

To try the design on other photos in your own editor, cut out the white background: POST /v1/rmbg-1.0/remove returns a PNG with alpha. API pricing lists Remove background at $0.0225 per image, plus a 5.5% agent fee by default, and remove background API covers the call.

Which fields does each step use?

Both steps are the same POST /v1/images request with different inputs. Only models that edit from references accept input_references; a text-to-image-only model rejects them.

What are the limits?

• The preview is a redrawn photo, not a simulation of ink in skin. The model repaints the whole image, so your arm, your skin, or an existing tattoo can change too.
• An artist decides what works on skin: line weight, size, and detail. Bring the AI design as a reference, not as a stencil.
• Today designs come back as PNG, JPEG, or WebP. No model lists svg, so there is no vector file.
• Each completed image is billed, and a failed one is not. ChatGPT Image 2.5 estimates each request's price from its size and quality, and usage.cost in the response is the USD amount billed.
• Results are Sume-hosted, signed URLs, so download the designs you keep.