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home / skills / masayan1126 / masayan-uni-code-plugins / thumbnail

thumbnail skill

/plugins/gen-ai-image-prompt-creator/skills/thumbnail

This skill generates Nano Banana Pro prompts for high-contrast blog and YouTube thumbnails, guiding title, platform, style, and visuals to boost click-through.

npx playbooks add skill masayan1126/masayan-uni-code-plugins --skill thumbnail

Review the files below or copy the command above to add this skill to your agents.

Files (4)
SKILL.md
1.8 KB
---
name: creating-thumbnails
description: Generates Nano Banana Pro prompts for blog and YouTube thumbnail images. Use when user mentions "サムネイル作成", "サムネ", "YouTube用画像", or "ブログ画像".
---

# サムネイル画像作成

## ワークフロー

1. **アイデア確認**: `progress/ideas.md` をチェックし、該当するアイデアがあれば提案
2. **プラットフォーム確認**:
   - ブログ: 1200x630 (OGP)
   - YouTube: 1280x720 (16:9)
3. **コンテンツ確認**: タイトル（20文字以内推奨）、テーマ
4. **スタイル選択**:
   - テキスト中心型
   - 人物・キャラ型
   - コンセプト型
   - 比較型
5. **キャラクター確認**（人物・キャラ型の場合）:
   - 既存キャラクター使用 → プロンプトに「画像生成AI使用時にベース画像添付」の注記を含める
   - 新規キャラクター → キャラクター詳細をプロンプトに記載
6. **AIっぽさ緩和オプション確認**: [ANTI_AI_STYLE.md](../ANTI_AI_STYLE.md) 参照
   - 「ベタ塗り」「デフォルメされたフォルム」を含めるか確認
7. **プロンプト生成**: PROMPT_TEMPLATE.md 使用
8. **成果物保存**:
   - プロンプト: `output/thumbnail/{タイトル}.md`（ディレクトリがなければ作成）
   - 生成画像: `output/thumbnail/images/{タイトル}.png`
9. **進捗更新**: `progress/ideas.md` を更新（完了したアイデアにチェック）

## 参照ファイル

- [FORMATS.md](FORMATS.md): フォーマット定義
- [PROMPT_TEMPLATE.md](PROMPT_TEMPLATE.md): テンプレート
- [EXAMPLES.md](EXAMPLES.md): サンプル

## 必須ルール

- 日本語テキスト
- 高コントラスト配色
- クリック率を意識したデザイン

Overview

This skill generates Nano Banana Pro prompts for creating high-impact blog and YouTube thumbnail images. It is triggered when users mention Japanese thumbnail keywords such as サムネイル作成, サムネ, YouTube用画像, or ブログ画像. The output includes platform-aware prompt text and saving instructions so you can feed prompts directly into image-generation tools. It focuses on high-contrast, click‑driving designs and keeps required language and format rules in mind.

How this skill works

The skill inspects your title and theme, checks an internal idea backlog, and selects the appropriate platform size (OGP for blogs or 16:9 for YouTube). It asks for the thumbnail style (text-heavy, character, conceptual, or comparison) and character details when needed, applies anti-AI style options, and then fills a prompt template to produce a ready-to-use Nano Banana Pro prompt. Generated prompts and file paths are suggested for saving prompts and images, and the idea backlog is updated to track progress.

When to use it

  • When you say サムネイル作成, サムネ, YouTube用画像, or ブログ画像
  • When you have a title (preferably ≤20 characters) and a clear theme
  • When you need platform-specific sizes (blog OGP or YouTube 16:9)
  • When you want a prompt tailored for Nano Banana Pro image generation
  • When you need guidance on character usage or anti-AI styling

Best practices

  • Provide a concise title (20 characters or fewer recommended) and a short theme description
  • Specify desired style early: text-centric, character, conceptual, or comparison
  • For existing characters, attach a base image when using image-generation AI
  • Choose high-contrast color schemes to increase click-through rate
  • Use the anti-AI style options to reduce obvious synthetic artifacts

Example use cases

  • Create a YouTube thumbnail prompt for a 1280x720 video about productivity tips
  • Generate a blog OGP prompt (1200x630) for an article titled within 20 characters
  • Produce a character-driven thumbnail prompt and include a base image note
  • Make a comparison-style thumbnail prompt highlighting 'Before vs After'
  • Convert an idea from the backlog into a finalized Nano Banana Pro prompt file

FAQ

What image sizes does the skill target?

It uses 1200x630 for blog OGP images and 1280x720 (16:9) for YouTube thumbnails.

How do I handle existing characters?

Indicate that a base image will be attached; the prompt will include a note to supply that image to the generation tool.