The spine calculations are for most people a confusing element. For the most cases, our client will implement the calculations directly into their system. For that, we provide the formulas for the calculations.
Spine in mm = (paperweight in gsm x paper bulk x (page count / 2)) / 1000 + (2 x cover thickness)
Spine in inch = ((paperweight in gsm x paper bulk x (page count / 2)) / 1000 + (2 x cover thickness)) / 25.4
|Paper type||Bulk value|
|Cover type||Thickness in mm|
|Case Wrap / Hardcover - 3 mm material (default)||3.0|
|Case Wrap / Hardcover - 2 mm material||2.0|
|Perfect Binding / Softcover||0.5|
We have made a guideline tool for you to easily calculate the spine based on the paperweight, paper type, and cover type.
You find the calculator here: Spine width calculator
This spine width calculation uses average bulk values. The characteristics of the paper used by different print partners may vary.
Case Wrap books mostly use pre-cut cardboard in the spine. The cardboard is therefore in a number of fixed sizes. These sizes may vary between print partners.