Concave or convex front trim (block draw)
Medium severitySymptoms
Front cut not straight: bowing in or out at the book's middle
Probable causes
- Thick block compressing into a wedge under the clamp
- rounded spine seating badly
- badly distributed pressure
The Print Guy · 2026-10-05
Other problems in this category
Three-knife trimmer · TPG-250
Rough, torn or flaky trim edges
Edges not smooth; torn paper; flaking on laminated covers
Three-knife trimmer · TPG-251
Clamp marks on the cover
Sunken or shiny rectangular imprint on book covers
Three-knife trimmer · TPG-254
Front and side cuts out of sync
Double mark at the corners; bitten or stepped corners
Three-knife trimmer · TPG-247
Variable sizes between books in one run
Inconsistent final format; some books shorter or narrower
Three-knife trimmer · TPG-248
Off-square cut (rhomboid book)
Head and foot not perpendicular to the spine; visibly crooked margins
Three-knife trimmer · TPG-249
Draw: cover or first pages pulled
Cover or top sheets shorter or with an inward-curved edge