Merch isn't "just printing the IP onto something." Different processes have different constraints: badges need few colors, T-shirts need to account for the printing process, mugs are curved surfaces. This skill first works byprocessto produce adapted artwork, then produces product mockups.
Belongs to brand-ip-kit-skills · Artwork Sunburst (clean line art) / Mockup Flare
Required inputs
- Category list and budget level (small-batch sampling / mass production)
brand/reference; whether text is needed (slogan, year, event name)- Style: brand standard / limited edition (holiday, collab, city)
Steps
- Process → artwork constraints(see table below), write one line of constraints per category, then write the artwork content.
- First produce flat artwork(Template A), on a white or transparent background, to facilitate subsequent vectorization and sampling.
- Then produce mockups(Template B / C), applying the flat artwork as a reference image onto the product.
- Keep a set of merch consistent: use the same "series theme" for the same series (e.g., Orange Season, Office Worker, City Limited Edition), with different poses but consistent props/color scheme.
- Production delivery: flat artwork must be vectorized or a 300 dpi bitmap; for badges, provide the factory with Pantone color numbers and metal line stroke specifications.
Process constraints quick reference
| Category | Process | Artwork requirements |
|---|---|---|
| Metal badge | Soft/hard enamel | ≤6 colors, each color block enclosed by metal lines, minimum line width ≈0.3 mm, common size 25–40 mm |
| T-shirt | Screen printing / direct-to-garment DTG / heat transfer | Screen printing is billed by number of colors (≤4 colors recommended); DTG can do gradients; chest small logo 8–10 cm, front/back large graphic 25–30 cm |
| Mug | Heat transfer | Print area approx. 20×8 cm wrap-around, leave 1–2 cm on each side of the handle |
| Canvas bag | Screen printing | Single color or two colors is most cost-effective, avoid large full-bleed areas |
| Acrylic keychain | UV printing + cutting | Add a 2–3 mm white border to the outer contour, leave a hanging hole |
| Plush toy | Sewing | Remove fine lines, change facial features to embroidered block shapes, proportions more chibi |
Prompt templates
A · Flat artwork (by process)
{LOCK}
Merch artwork for a {item} made with {process}: {IP name} {pose} {+ props}, {text: "{text}" spelled exactly | no text}.
Constraints: max {n} flat colours from {HEX list}, {closed outlines for enamel | no gradients | thick outlines}, centred on pure white, print-ready look, no mockup.
B · Single-item mockup
Photorealistic product photo of a {colour} {item} printed with the artwork from image 1 ({placement and size, e.g. 9 cm wide on left chest}).
Correct {fabric folds / mug curvature / enamel shine}, {setting}, soft natural light, lifestyle catalogue style.
C · Full merch family portrait
{LOCK}
Photorealistic merch collection flat-lay on {surface}: {item list with designs}. Same series theme "{theme}", consistent palette {HEX}, natural window light, top-down.
D · Plush / soft vinyl figure sampling image
{LOCK}
Product design render of a {plush toy | vinyl figure} of {IP name}, {height} cm, {material}, simplified for {sewing | moulding}: embroidered eyes, no thin lines.
Front and 3/4 view side by side, white studio background.
Quality checklist
- Artwork meets process constraints (color count, line width, white space)
- Text is correct character by character; no long sentences on small sizes (badges)
- In the mockup, the artwork is not distorted and its position matches the real print area
- A set of merch belongs to the same series theme
- Already reminded: sample before mass production, color difference subject to the actual product
Common failures & fixes
| Symptom | Fix |
|---|---|
| The badge design has gradients/shadows, which the factory can't produce | Add "flat colours only, closed outlines, enamel pin artwork" |
| The T-shirt mockup design floats on top of the shirt | Write "printed into the fabric, follows folds"; or use a PS displacement map |
| The mug design is cut off by the handle | Clearly state "design centred on the side opposite the handle" |
| The plush sample render looks too much like an illustration | Emphasise the material: "fuzzy fabric texture, visible seams" |
How to render · How to render
| Route | Condition | Method |
|---|---|---|
| ① Built-in tool | The agent has its own image generation (Codex imagegen, ChatGPT, etc.) | Call it directly, using the reference images in brand/ref/ as input images |
| ② API Key | Set GPTIMAGE_API_KEY, optionally GPTIMAGE_BASE_URL(any OpenAI-compatible gateway; if you don't have an official key you can use https://tryallapi.com/v1） |
python scripts/generate.py --model flare --image brand/ref/ip-sheet.png --size 1024x1024 --prompt-file p.txt --out out/x.png |
| ③ Neither | — | Output the final prompt + a list of reference images to upload, so the user can paste them into any image generation tool that supports reference images |
Model routing: defaults to GPT Image 2.5 Flare（gpt-image-2.5-flare, fast, suitable for drafts and scenes); when the image contains a wordmark/Chinese title that must be letter-perfect, or when doing a "change only one thing" local edit, switch to Sunburst（gpt-image-2.5-sunburst). The prompt itself is model-agnostic: it also works with Gemini / Seedream / Midjourney, etc., but for models with weak text rendering, leave the text blank and add it in post-production.