How To Design A French Flap Cover For Your Book...
Use the below calculations to design your french flap cover.
The spine width is equal to the text bulk plus .034”
Calculation: # of pages / PPI (pages per inch) = Text Bulk
Text Bulk + .034 = Spine Width
Example: (300/513ppi) = .584 Then, .584+.034 =.618 (Spine Width)
B. Front/Back Cover Width
Front and Back cover width is equal to the trim size of your book plus .125”. This measurement is the same as the Case Bound Front/Back cover plus the hinge.
The front and back flaps are typically around 3.5”. The flaps can not be larger than the trim size of the book.
D. Front/Back/Spine/Flap Height
The height is equal to the trim size of your book plus .25”. This measurement is the same size as the Case Bound Front/Back Cover.
The bleed in the dust jacket is to ensure a proper trim so there is no white around the cover. The bleed is .125”.
F. Overall Height
Calculation: E+D+E = Overall Width
G. Overall Width
Calculation: E+C+B+A+B+C+E = Overall Width
You can download an interactive version of this template here.