Book formats and trim sizes explained
6×9, 8×10, 8.5×11 or 8.5×8.5 square — what each trim size is best for and how it changes your pages and cover.
The trim size is the physical width × height of the printed page. You pick it in Step 2 (Settings), and it shapes everything downstream: how illustrations are framed, how the layout breathes, and the exact dimensions of your wraparound cover. Coloring Books Maker supports the four trim sizes that cover almost every coloring book on the market.
supported
All four sizes above are drawn to true relative scale. The covers are real books generated in the app — we haven't published a 6″ × 9″ showcase book yet, so that one is shown as a plain page.
8.5″ × 11″ — the classic (most popular)
Letter size. The default for kids' coloring books and the safest commercial choice — big pages, generous drawing area, familiar to buyers. If you're unsure, start here. Our “Ocean Friends”, “Dinosaur Adventure” and “Retro Road Trip” showcase books all use it.
8.5″ × 8.5″ — the square
Square pages feel playful and giftable, and square illustrations compose beautifully for simple, centered subjects. A favorite for toddler books (ages 3–5) where one big friendly character fills the page — like our “Sweet Treats Party”. Note that the AI generates square illustrations for this format, so scenes are framed differently than in portrait books.
8″ × 10″ — the compact large format
Slightly smaller and narrower than letter, with a premium feel in hand. Good for tweens and doodle-style books — “Cosmic Doodles” on our landing page is an 8×10. Printing costs at most print-on-demand services are the same as 8.5×11, so the choice is aesthetic.
6″ × 9″ — the paperback
The standard novel size. For coloring books it's a niche pick: portable “purse-sized” books, travel activity books, and intricate adult designs where small, dense pages are part of the charm. Pages are noticeably smaller, so favor medium detail over sprawling scenes.
Which one should you pick?
- Kids 3–5: 8.5×8.5 square or 8.5×11
- Kids 6–12: 8.5×11, or 8×10 for a slightly premium feel
- Adults: 8.5×11 for detailed scenes; 6×9 for travel-sized books
- Gift books: 8.5×8.5 square stands out on a shelf
The trim size is set per project, and the cover spread is computed from it automatically — including spine width from your final page count (see Designing your cover).