Perfect Binding Requirements

Technical specifications for file preparation and production

Text Block Requirements

Spine Grind Allowance

Standard
1/8 inch Default for layout calculations
Minimum (digital/hand-fed)
1/16 inch Absolute minimum
Maximum
1/4 inch Requires advance approval

32+ page folded signatures may require additional grind. Position all live content and critical images at least 1/8 inch from the binding edge.

Bleeds

Head
1/8 inch
Foot
1/8 inch
Face
1/8 inch

Side Glue Clearance

First and last pages
3/16 inch Clear of ink, varnish, and critical content along spine edge
Hinge area
1/4 inch

Glue-free zone ensures proper adhesion between cover and text block.

Signature Construction

Perforation
Light perforation on spine and head folds Allows flat laying
Stacking orientation
High-folio up
Lap requirement
None

Two-Page Inserts / Fly Sheets

Preferred placement
Between signatures
Avoid
Front or back of book
Size
Should match text dimensions

Front/back placement may require hand-feeding, increases cost, and causes higher spoilage.

Size Constraints

Spine-to-Face (Trimmed)

Minimum
2.75 inches
Maximum
11.75 inches

Spine-to-Face (Untrimmed)

Maximum
12.25 inches Includes grind + face bleed

Head-to-Foot (Trimmed)

Minimum
4.25 inches Or 2-up binding

Text Block Thickness

Minimum
0.060 inches
Maximum
2.3125 inches

Books under 0.07 inch thick require sample materials for feasibility testing before production.

Cover Requirements

Glue Traps

Foot (bottom)
1/4 inch beyond untrimmed text 1/8 inch minimum
Head (top)
1/16 inch Soft head
PUR binding
Mandatory
EVA binding
Recommended

Inside Cover Glue-Free Zones

Spine area
Full width after grind No ink or coating
Side glue zones
3/16 inch Extending from spine onto front and back inside covers

Cover Specifications

Hinge score (default)
1/4 inch Applied to all perfect bound covers
Minimum flat width
8.5 inches Face-to-face measurement
Grain direction
Must run parallel to spine

Cross-grain consequences: text may wrinkle, covers may crack. May require letterpress scoring at additional cost.

Cracking Prevention

Lamination
Available
Letterpress (LP) scoring
Available
Flood UV coating
Available

These services are not included in standard bids unless explicitly stated.

Spine Width Guidance

The bindery does not calculate spine widths from paper specifications.

Required process
Submit sample materials for bindery rule-up Or request dummy book (fee applies)
Prepress action
Do not estimate spine widths internally

Quick Reference

Text (Guts)

  • 1/8 inch clear zone at binding edge
  • 1/8 inch bleed on head, foot, face
  • 3/16 inch clear at spine for side glue (first/last pages)
  • Light perforations on folds
  • High-folio stacking
  • No lap
  • 2-page inserts between signatures only
  • Thickness: 0.060–2.3125 inches
  • Spine-to-face under 12.25 inches

Cover

  • 1/4 inch glue trap at foot; 1/16 inch at head
  • Ink/coating-free zones in spine + 3/16 inch side glue areas
  • 1/4 inch hinge score accounted for in layout
  • Minimum 8.5 inches flat width
  • Grain parallel to spine
  • Cracking risk assessed; LP score/lamination specified if needed
  • Imposition verified for adequate margins
  • Spine width confirmed via rule-up