# Ad Designer > Generate marketing ad images using Nano Banana Pro (Gemini 3 Pro Image). Accepts campaign-planner creative briefs, reads brand bible for visual style, constructs marketing-optimized prompts, and produces platform-ready images at correct aspect ratios. Supports 1:1, 9:16, 16:9, 4:5 formats. Includes self-review loop to catch hallucinated logos, wrong text, and quality issues. Draft-first workflow (1K fast iteration, 4K final). Outputs to /tmp/marketing/assets/images/. - Skill: `modbender/ad-designer` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add modbender/ad-designer` - Raw SKILL.md: https://api.skillmd.com/api/skills/modbender/ad-designer/raw - Safety review: pending (external: skill-scanner WARNING, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Marketing & Growth - Author: modbender (https://skillmd.com/u/modbender) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/modbender/ad-designer --- # Ad Designer Generate marketing ad images from campaign-planner creative briefs. Wrap nano-banana-pro with brand-aware prompt construction, aspect ratio handling, and a self-review loop that catches quality issues before marking images final. ## Roles - **Ad Designer** (this skill) — sole executor - **nano-banana-pro** — image generation engine (upstream dependency) - **campaign-planner** — upstream source of creative briefs - **brand-bible-builder** — upstream source of brand visual identity --- ## Prerequisites Verify before starting: ```bash command -v uv test -n "$GEMINI_API_KEY" test -f ~/.codex/skills/nano-banana-pro/scripts/generate_image.py ``` If `uv` is missing: tell the user to install it with `curl -LsSf https://astral.sh/uv/install.sh | sh`. If `GEMINI_API_KEY` is unset: tell the user to export it from Google AI Studio. If the script is missing: tell the user the nano-banana-pro skill must be installed first. --- ## Step 1: Collect Inputs Identify which inputs are present in the conversation or filesystem: | Input | Source | Where to find it | |-------|--------|-----------------| | Creative brief(s) | campaign-planner skill | `/tmp/marketing/campaigns/-campaign-plan.json` → `ad_creatives[]` array, or inline in conversation | | Brand bible | brand-bible-builder skill | `/tmp/marketing/brands//brand-bible.md` or inline | | Aspect ratio | User or brief | Defaults to 1:1 if not specified | | Resolution mode | User | Defaults to draft (1K) unless user says "final" or "4K" | If the creative brief is missing, ask: > "I need a creative brief to generate the ad. Run `/campaign-planner` first, or paste the brief details: headline, visual direction, CTA, and target audience." If the brand bible is missing, proceed with neutral visual defaults — note this in the output and recommend running `/brand-bible-builder` for on-brand results. --- ## Step 2: Read Brand Bible Visual Identity Open the brand bible and extract these fields into a working reference: - **Primary colors** — hex codes or descriptors (e.g. `#1A2E5A deep navy`, `#F5A623 amber`) - **Secondary / accent colors** — supporting palette - **Font style** — serif vs sans-serif, weight, mood descriptor (e.g. "bold geometric sans", "light editorial serif") - **Imagery style** — photography vs illustration, lifestyle vs product-only, color grading mood (warm/cool/muted/vibrant) - **Layout pattern** — minimal and clean vs content-dense, whitespace-heavy vs layered - **Tone** — formal, casual, bold, playful, premium, approachable Keep this as a 6-field internal reference. Do not show it to the user. Use it when constructing prompts in Step 3. --- ## Step 3: Construct Image Generation Prompt Apply these rules every time. They are non-negotiable. ### Core Rules (from best-practice image generation) **Rule 1 — Less is more.** Short, focused prompts outperform long descriptive ones. Target 15–30 words for the visual description. Cut adjectives that repeat the same idea. **Rule 2 — No logos, brand names, or company names.** Never include the brand name, product name, logo description, or any trademark in the prompt. The generation engine hallucinates these badly and they must be added in post-production. **Rule 3 — Only include text that is explicitly specified.** If the brief specifies a headline to appear in the image, include it exactly as written — no paraphrasing. If no text is specified, do not add any text to the prompt. Do not include CTAs, taglines, or copy unless the brief explicitly says to render text. **Rule 4 — Describe emotion and composition, not data.** Instead of "a woman saving money on her bills," write "confident woman, bright home office, warm morning light, relaxed expression." The emotion communicates the message; the model handles the rest. **Rule 5 — Translate brand colors without naming the brand.** Convert hex codes to descriptors: `#1A2E5A` → "deep navy", `#F5A623` → "warm amber". Use these color words in the prompt naturally. ### Prompt Construction Formula Assemble the prompt in this order: ``` [SUBJECT] — who or what is the focal element [SETTING] — environment or background context [MOOD / EMOTION] — feeling the image should evoke [COMPOSITION] — framing, shot type, perspective [LIGHTING] — quality and direction of light [COLOR PALETTE] — 2–3 colors derived from brand bible [STYLE] — photography/illustration style from brand bible [AVOID] — explicit exclusions (text, logos, clutter, etc.) ``` Do not use all 8 fields every time. Use only those relevant to the brief. A 5-field prompt is often stronger than an 8-field one. ### Example Construction Brief input: ``` headline: "Finally, sleep that works" visual_direction: "Woman waking up refreshed, natural light bedroom" cta: "Try free tonight" target_persona: "Aisha, 28, KL, stressed professional" ``` Brand bible: warm coral `#E8735A`, off-white `#FAF7F2`, editorial sans-serif, warm and minimal photography style. Constructed prompt: ``` Young woman waking up peacefully, sunlit minimalist bedroom, linen textures, warm coral and off-white tones, soft morning light through sheer curtains, close-up on relaxed expression, warm editorial photography style ``` What was excluded: brand name, CTA text, product name, headline text (no text was specified for visual rendering). --- ## Step 4: Select Aspect Ratio Map the brief's platform or format to the correct ratio flag and pixel dimensions: | Platform / Format | Ratio | Pixel Dimensions | Use Case | |-------------------|-------|-----------------|----------| | Instagram / Facebook Feed | 1:1 | 1080 × 1080 | Square feed post | | Instagram Story / Reel | 9:16 | 1080 × 1920 | Full-screen vertical | | Facebook Feed (portrait) | 4:5 | 1080 × 1350 | Taller feed post, more screen area | | YouTube / LinkedIn Cover | 16:9 | 1920 × 1080 | Landscape / banner | If the brief does not specify a platform, default to 1:1. For carousel ads: generate all cards at the same ratio. Use 1:1 unless the brief specifies otherwise. Pass the ratio to the script via `--resolution`. The nano-banana-pro script handles internal sizing. Generate at 1K for drafts, 4K for finals. --- ## Step 5: Generate Images Create the output directory: ```bash mkdir -p /tmp/marketing/assets/images ``` ### Single image generation Use this command pattern. Always use absolute path for the script. ```bash uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py \ --prompt "" \ --filename "/tmp/marketing/assets/images/--draft.png" \ --resolution 1K ``` Filename format: `yyyy-mm-dd-hh-mm-ss--draft.png` - `brief-id`: lowercase kebab-case derived from the brief headline (e.g. `finally-sleep-works`) - Use current date/time for timestamp ### Draft-first workflow Always follow this sequence: 1. **Draft at 1K** — generate first at 1K for fast feedback. Present to user. 2. **Iterate** — if issues found in self-review (Step 6), adjust prompt and regenerate at 1K. Max 3 attempts. 3. **Final at 4K** — only after user approves the draft or after self-review passes. Change filename suffix from `-draft` to `-final`, set `--resolution 4K`. ### Carousel ads Generate each card as a separate image. Naming convention: ``` yyyy-mm-dd-hh-mm-ss--card-01-draft.png yyyy-mm-dd-hh-mm-ss--card-02-draft.png ``` Ensure visual consistency across cards: - Use the same color palette descriptor in every card's prompt - Use the same style descriptor in every card's prompt - Use the same lighting descriptor in every card's prompt - Vary only the subject and composition per card --- ## Step 6: Self-Review Loop (CRITICAL) After generating each image, perform a structured self-review before presenting to the user. Do not skip this step. Run through this checklist for every generated image: | Check | Pass Condition | Fail Action | |-------|---------------|-------------| | Text accuracy | Any specified text appears correctly and is readable | Simplify prompt; add explicit text instruction | | No hallucinated logos | No brand marks, wordmarks, icons, or watermarks visible | Add "no logos, no text, no watermarks" to avoid clause | | No hallucinated brand names | No company names or product names rendered as text | Add "no brand names, no product names" to avoid clause | | Aspect ratio | Matches requested format | Re-run with correct ratio flag | | Color alignment | Dominant colors match brand palette intent | Strengthen color descriptors in prompt | | Overall quality | Image is coherent, professional, on-brief | Rebuild prompt from scratch using simpler structure | ### Fail response If any check fails: 1. Identify the specific failure from the table above. 2. Apply the corresponding fail action to the prompt. 3. Regenerate at 1K. 4. Re-run the self-review checklist on the new image. 5. Stop after 3 total attempts. If still failing on attempt 3, present the best result to the user with a note explaining what the issue is and what was tried. Do not present a failing image silently. Always tell the user what was wrong and what fix was applied. --- ## Step 7: HITL — Present for User Review After self-review passes (or after 3 attempts), present the results: ``` Ad image(s) generated for: [brief headline] Draft(s) saved to /tmp/marketing/assets/images/: [timestamp]-[brief-id]-draft.png ← [ratio] | 1K Self-review: [PASS / notes on any issues found and fixed] Review the image and reply with one of: A) Approve → I'll upscale to 4K final B) Adjust → describe what to change C) Skip → move to next brief ``` Wait for the user's response before generating the 4K final or moving to the next brief. If the user says "adjust" or describes changes: - Apply the change to the prompt (keep changes minimal — one diff at a time) - Regenerate at 1K - Re-run self-review - Present again If the user approves: - Regenerate at 4K with `-final` filename suffix - Confirm: "Final saved: `/tmp/marketing/assets/images/[filename]-final.png`" --- ## Step 8: Process Multiple Briefs If the input contains multiple briefs (e.g. from a campaign-planner JSON with 3–5 image ad entries), process them sequentially. Complete the full cycle (generate → self-review → HITL approval → final) for each brief before moving to the next. After all briefs are processed, present a summary: ``` All ad images complete. Generated: /tmp/marketing/assets/images/[file-1]-final.png [ratio] /tmp/marketing/assets/images/[file-2]-final.png [ratio] /tmp/marketing/assets/images/[file-3]-final.png [ratio] Next step: run /meta-ads-publisher to upload these to your ad account, or /campaign-planner to review the full campaign. ``` --- ## Error Handling | Error | Action | |-------|--------| | `Error: No API key provided.` | Tell user to run `export GEMINI_API_KEY=` and retry | | `Error loading input image:` | Verify the `--input-image` path exists; fix path and retry | | `quota / 403 / permission` API error | Wrong key or quota exceeded; ask user to check Google AI Studio quota | | Script not found at `~/.codex/skills/...` | nano-banana-pro skill is not installed; tell user to install it from ClawHub | | `uv: command not found` | Run `curl -LsSf https://astral.sh/uv/install.sh | sh` then retry | | Image generation returns blank/empty | Prompt may be too restrictive; remove avoid clauses and simplify to subject + style only | --- ## File Paths Reference ``` /tmp/marketing/ ├── assets/ │ └── images/ │ ├── yyyy-mm-dd-hh-mm-ss--draft.png ← draft outputs │ └── yyyy-mm-dd-hh-mm-ss--final.png ← approved 4K finals ├── brands// │ └── brand-bible.md ← brand visual reference └── campaigns/ └── -campaign-plan.json ← input brief source ```