French Flaps

French flaps are extensions of a softcover that fold inward behind the front and back cover panels. They provide space for additional content while giving the fore edges a more structured feel.

The flaps remain attached to the cover and cannot be removed like a dust jacket. The finished book is still flexible because the construction does not use rigid cover boards.

How a French Flap Cover Is Built

The complete cover is produced from one continuous sheet containing the back flap, back cover, spine, front cover and front flap. The two outer panels are scored at the fore edges and folded inward.

French flaps are commonly used with perfect-bound and section-sewn softcover books. They describe the cover construction rather than the method used to join the pages.

This format may also be called a gatefold softcover or flap paperback. Showing the complete flat layout on the quotation or proof prevents it from being confused with a removable jacket.

Choosing a Practical Flap Width

A width of 80–100 mm per flap works for most portrait softcover books. An 80 mm flap usually provides enough space for a short synopsis, author biography or series introduction.

Use 90–100 mm when more text or larger images are required. Flaps below 60 mm provide little usable space and may not remain neatly folded inside the cover.

The front and back flaps normally use the same width. A flap wider than approximately two-thirds of the front cover can add unnecessary bulk, so a wider construction should be confirmed before the artwork is prepared.

The complete flat width is:

Back flap + back cover + spine + front cover + front flap

Bleed is added outside this finished flat size. The calculation method is explained in Flat Size for Printing.

Prepare the Cover Artwork

Work from the Final Template

Confirm the page count and interior paper before preparing the cover. Both affect the final spine width, so changing either after the artwork is complete can move the front, back and flap panels out of position.

The production template should show the spine, hinge and flap-fold lines. Do not divide the extended cover into equal sections or estimate the folds from a visual mock-up.

Guidance on positioning structural folds is available in Fold Lines for Book Printing.

Add Bleed and Protect Important Content

Add 3 mm bleed around the outside edge of the complete flat cover. Internal fold lines do not need separate bleed.

Keep titles, logos, barcodes, faces and small text at least 5 mm away from the flap folds. Background colors and full-bleed images can continue across a fold, but the design should allow for slight movement during scoring and folding.

The same clearance should be considered around the spine and hinge areas shown on the template. More information is available in Safe Area for Printing.

Set Up the Inside Artwork

If the inside cover and flaps will be printed, supply a separate inside artwork page using the same flat dimensions and fold positions as the outside cover.

Do not create the inside by simply mirroring the outside artwork. Check the front and back flap content on a folded proof to make sure all text faces the correct direction.

For perfect binding, readable content should remain clear of the side-glue areas beside the spine. If foil stamping, Spot UV or another registered finish is used, place it on a separate production layer and avoid running fine details across the flap folds.

Choose a Cover Paper That Folds Cleanly

Coated paper between 250 and 300 gsm is a practical range for most French flap covers. A 250 gsm sheet produces a more flexible cover, while 300 gsm gives the fore edges a firmer feel.

A 350 gsm cover can become too stiff for smaller books and may spring outward after folding. It should only be selected after checking a folded sample.

C2S paper is suitable when both sides require full-color printing. C1S paper can be used when the exterior needs a coated printing surface and the inside flaps contain simpler text or intentionally use a softer uncoated appearance.

The main coated paper options are explained in Coated Paper for Printing.

Scoring, Grain Direction and Lamination

Paper grain should run parallel to the spine and flap folds. This allows the cover to bend more naturally and reduces resistance along the creases.

The flap folds must be scored before folding, particularly when the cover has heavy ink coverage or lamination. Folding a thick coated sheet without a suitable score can produce white cracking or an uneven crease.

Lamination protects the printed surface but does not remove the need for scoring. The paper, film and crease should work together without the laminate lifting or splitting around the folds.

Suitable film options are compared in Lamination for Printing.

Binding and Trimming French Flap Covers

French flaps are frequently combined with Perfect Binding. They can also be used on section-sewn softcovers when the cover-feeding and trimming process supports the extended panels.

The folded panels sit behind the fore edges, so they cannot pass through every standard paperback trimming process unchanged. The book block may be fore-edge trimmed before the flap cover is attached, or the printer may use equipment designed to keep the flaps away from the cutting path.

This production method should be confirmed before the final cover template is issued, especially when the book uses wide flaps or an unusually large finished size.

Check the Finished Sample

Both flaps should fold evenly and remain inside when the book is closed. They should not press against the book block or resist normal opening.

Check dark printed areas for white cracking along the scores and inspect laminated covers for lifting around the folds. The spine should remain centered, and the hinge areas should allow the front and back covers to open without pulling the first or last pages.

For two-sided printing, confirm the orientation and position of all inside content on the completed book. A flat proof can confirm the layout, but only a bound sample shows the final folding tension, opening behavior and trimming result.