AI Image Generation

Beginner · 10 min read · By Chitmunk Team · Updated Oct 18, 2026

Prototype with real pictures today, then commission an artist when the game is ready for print. Chitmunk generates AI card art directly in the editor. Write a prompt, pick a size, and the image drops onto your canvas. Rare includes 100 credits per month; Epic 500. Every new account gets 10 starter credits, and the 7-day free trial gives you Rare's 100, so you can try it before subscribing. Prompts can include {{Column Name}} tokens to generate unique art per spreadsheet row in a single batch, handy when you need 60 monster portraits from one spreadsheet. This guide covers writing prompts that work, sizing for card art slots, spreadsheet-driven batches, and managing your credit budget so you don't burn the month's allowance on one re-roll. For the full panel (styles, variations, card frames), see The Acorn Cauldron.

Under the hood: AI art is powered by FLUX (Black Forest Labs), running on Cloudflare Workers AI.

Your AI Credits

Rare and Epic include a monthly allowance of AI credits. One card-sized image at 1024 × 1024 pixels costs 20 credits, and that is the most common size for print-quality card art.

A typical card game has 50–150 unique cards, so plan your credits: draft at 512 × 512 (5 credits each), and keep full-size images for the cards that matter. New accounts also get 10 starter credits once, and they never expire.

Your monthly credits reset on your subscription anniversary. Unused monthly credits do not roll over.

Image Sizes

Smaller images use less of your budget; larger images use more. Every 512 × 512 block of an image costs 5 credits, and the Cauldron shows the exact cost beside the Brew button before you commit. The image is made at the size of the image box you open it from, up to 2048 × 2048.

Getting Started

To generate your first AI illustration:

1. Open the AI generator: Click the Ai Image button in the Add toolbar to add a new placeholder and open the Acorn Cauldron, or select an existing image and click Generate with AI in the inspector (right-clicking the image and choosing Generate AI Image works too).
2. Write a prompt: Describe the image you want. Be specific about the subject, style, and mood.
3. Brew: Click the Brew button. The results appear in the panel; click one to put it on your card.

If you open the generator from an existing image, the image you pick replaces that image. Without a target, it is added to the card as a new image.

Writing Good Prompts

The prompt is a text description of the image you want the AI to create. Be specific about the subject, style, and mood:

A fierce red dragon perched on a rocky cliff, fantasy illustration, dramatic lighting, detailed scales, dark stormy sky background

Tips for better results:

• Be specific: "A knight in silver armor holding a glowing sword" works better than "a knight."
• Include style keywords: "digital painting," "fantasy illustration," "pixel art," or "watercolor" guide the artistic style.
• Describe the background: Mention what is behind the subject to avoid random or cluttered backgrounds.
• Keep it consistent: Use the same style keywords across all cards in a deck for a cohesive look.

Spreadsheet-Aware Prompts

This is where a spreadsheet pays off twice. If you have a spreadsheet linked, your columns show up as pills under the prompt box, and you can use the same {{Column Name}} syntax as in text boxes.

A {{Type}} creature called {{Name}}, fantasy card game illustration, detailed, vibrant colors

With your data, this prompt generates unique art for every card automatically:

• "A Dragon creature called Fire Drake..." for the first row
• "A Construct creature called Stone Golem..." for the second row
• "A Rogue creature called Shadow Thief..." for the third row

The more specific your prompt is to each card, the better the results. Use multiple columns to give the AI rich context.

Batch Generation

When you have a spreadsheet linked, the button reads "Brew 60 cards" (your row count) and Chitmunk generates art for every row in one batch, one after another. By default each row gets 4 variations; switch to 1 image to spend a quarter of the credits.

While It Runs

A counter shows how far along it is (e.g. "12 / 60"). Click Cancel at any time to stop after the image in progress (it still counts). Images already generated are kept, the rest are skipped. You can also close the panel; the brew keeps going and finished images are saved under Brewed.

Results

When the batch finishes, every generated image appears in a grid. Review them at a glance, then click Put on all N cards to place each row's first image on its card, or click a specific image to use it. Brew again runs the whole batch again; there is no way to re-roll just one card, so check a prompt on a single card before you commit the deck.

Best Practices

• Draft small, finalize big: Brew at 512 × 512 to iterate on prompts, then brew your final picks in a 1024 × 1024 or larger image box.
• Check a few cards before you commit to the whole deck: AI results vary: try the prompt on one important card first (without pills), and use Brew again if the batch didn't land.
• Combine columns: Put several spreadsheet columns in one prompt so the art fits each card.
• Keep your best prompts: Once you find a style that works, keep those style keywords consistent across your entire deck. The Cauldron remembers the prompt and style for each game.