When you configure your book on our Perfect Bound Book page, we automatically calculate your spine width based on your selected paper and page count.
You’ll see this spine width shown in the builder. This number is extremely important and needs to be added to your cover file.
For example: If you’re ordering a 5.5" x 8.5" book and the spine width shows 0.16", your full cover file (spread) will need to be:
Front cover = 5.5"
Spine = 0.16"
Back cover = 5.5"
Total width = 11.16" x 8.5"
How to set this up:
Use Adobe Illustrator or InDesign
Build your layout as one flat spread (back + spine + front)
Set trim size as your final size, and include 0.125" bleed on all sides
Tip: Always check the live spine width shown during your order. That’s the number you’ll use in your file. If you're unsure, just send us your artwork — we’ll check it before print.