Sticker pack: 12 transparent stickers with GPT Image 2.5 in 3 calls

Twelve transparent stickers take three n: 4 calls to ChatGPT Image 2.5 with background: "transparent", and cost $0.7905 at the catalog's high-quality 1024 rate of $0.065875 per image. ChatGPT Image 2.5 (the Flare and Sunburst ids) is the only family in the Sume image catalog that lists the background parameter.

That makes it the path for stickers, icons and cut-out props without a separate background-removal step. Everything below is from the Sume Image API docs and catalog (read 2026-10-03).

The numbers

quality omitted defaults to high; low and medium cost less, and xhigh and max cost more. For flat sticker art the lower tiers are worth a test before the full run.

Making the sticker set consistent

Write one style sentence (line weight, palette, border) and reuse it word for word in all twelve prompts, changing only the subject. For a mascot set, pass the first approved sticker as an input_references item in the later calls; the model accepts up to 16.

Ask for a white border and no shadow so edges stay clean on any background, and keep output_format at png or webp: JPEG has no alpha channel, so a transparent request saved as JPEG loses the transparency.

• One subject per image, centered, with margin on all sides.
• Check the alpha channel on a sample before you batch the other eleven.
• Platform sticker limits (size, bytes) apply after generation; resize in your own step.

The request

Repeat with a different subject line for each sticker. n up to 4 returns four variants per call.

{
  "model": "openai/gpt-image-2.5",
  "prompt": "Die-cut sticker of a smiling croissant, thick white border, flat colors",
  "background": "transparent",
  "output_format": "png",
  "n": 4
}