How to Save on AI Credits

Coloring Book Engine is designed so that wasted credits require deliberate effort. Here’s the full picture of where money is spent and how to spend less of it.

Where Credits Go (and Don’t)

Spends credits	Free (local)
Sketch generation & edits	Sketch Process and Vectorize
Coloring via API (& edits)	Coloring via GPU mode, palette/adjust, Finalize
Matter & cover AI generation	Book export, validation, 3D preview
Plan chat & one-time image analysis (cheap — text-scale)	The entire Assets & Videos pipeline

The Habits

1. Run Rest is the default. It only fills empty slots — finished pages are never re-billed. Reach for Run All only when you genuinely want to redo everything (and it will warn you and back up the old images first).
2. Draft on Cost, finish on Quality. Iterate your prompts and plan on the cheap tier; flip the toggle for the final pass on pages that earned it.
3. Fix pages one at a time. A page you dislike costs one credit to redo — click that card, don’t re-run the batch.
4. Refine instead of regenerate. The edit dialog’s “Additional requirements” mode adjusts the existing image; it’s more predictable than a fresh roll of the dice, so you converge in fewer attempts.
5. Front-load the Plan stage. Every hour in Plan (free) sharpens prompts that would otherwise burn credits on mediocre generations. Mention only the characters a page needs — each {Name} reference adds a little to the request.
6. GPU coloring for volume. If your machine can run it, GPU mode colors unlimited pages for electricity money.

The Built-in Protections

Even if you ignore all of the above: finished pages are never silently regenerated, Run All always warns and backs up, two consecutive failures pause the queue instead of burning through retries, and generation is paced to respect provider rate limits.