Cermify · Error Library · KDP

Cover · C-RATIO

Front-only cover uploaded where full wrap is required

The upload appears to be a front-only cover, but KDP paperback export needs a full wrap that includes back cover, spine, and front cover.

Severity
error
Automatic repair
Manual / guided
Submission impact
KDP: reject
Rule ID
C-RATIO
Error: Front-only cover uploaded where full wrap is required
Category: Cover
Severity: error
Auto Repair: Not automatic
Rule ID: C-RATIO
Affected: KDP=reject, Apple=unknown, Google=unknown, Kobo=unknown
Check this automatically with Cermify

Why this happens

How platforms treat it

PlatformResult
KDPreject
Apple Booksunknown
Google Playunknown
Kobounknown

How Cermify detects it

  1. Classify upload kind (front_only vs full_wrap) from aspect/metadata.
  2. When paperback full wrap is expected, flag front-only as C-RATIO.
  3. Often co-occurs with C-TRIM / C-BLEED size failures.
  4. Do not auto-invent spine/back artwork.

Automatic repair

Manual/guided only. Converting front-only to full wrap requires new design decisions for spine and back cover.

Manual fix

  1. Download or create a KDP full-cover template for your trim, page count, and paper.
  2. Place back, spine, and front art on the correct panels.
  3. Export the entire wrap (with bleed if required).
  4. Re-upload; confirm C-RATIO and C-TRIM are clear.

Examples

Paperback print needs a full wrap, not a front-only ebook cover.

Incorrect

upload.kind = front_only
Aspect ≈ trim front (e.g. 6×9)

Correct

upload.kind = full_wrap
Aspect ≈ (back + spine + front) × height with bleed

FAQ

Can Cermify mirror my front cover onto the back?

No. Back and spine need intentional design; blind mirroring is not offered.

I only needed an ebook cover—why this error?

You are on the paperback wrap path. Use the ebook cover flow for front-only assets.

Relation to C-TRIM?

Front-only files almost always fail wrap size checks too. Fix C-RATIO by building a real wrap; C-TRIM then validates dimensions.

Related errors

References