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6. Levels of Defect

6.1 Adhesive Case Hard Cover

Flexes Defect
251-299 Minor
201-250 Major
200 and less Critical – Not Acceptable

6.2 Adhesive Soft Flexible Cover (Paperbacks)

Flexes Defect
151-199 Minor
101-150 Major
100 and less Critical – Not Acceptable

6.3 Curl

The curl test is performed to evaluate the flatness of the cover boards of a case hard cover book, whether sewn or adhesive bound.

6.3.1 Curl Test Method

  • The curl test is carried out at a relative humidity of 50 ± 2% at 21° C (70° F), with the samples in equilibrium with these condition.
  • The instrument used for testing curls is made of a micrometer dial gauge mounted above a sheet of plate glass. The gauge is used to measure the maximum height of the case hard cover.
  • The warp is the thickness (bulk) of the cover subtracted from the height as measured by the micrometer. The curl measurement is recorded.
  • Whether the curl is convex or concave is recorded.

6.3.2 Level of Defect

A curl test warp of 3 mm or greater is a critical defect and is unacceptable for any hard cover book.

6.4 Damaged Pages

The percentage of gusseting-unwanted folds or creases-shall not exceed the tolerances shown below.

The percentage of dog ears-improperly trimmed or folded coners-shall not exceed the tolerances shown below.

The percentage of connected or torn pages shall not exceed the tolerances shown below.


These quality requirements apply to volumes bound or rebound for library use. These apply in addition to the quality requirements for binding described elsewhere in this document.

6.5 Warping Pages or Covers

The maximum deviation perpendicular to the hor

Prestige Library Informational Office Utility
0 mm 0.8 mm 1.0 mm 1.3 mm 2.5 mm
(0 in.) (0.03 in.) (0.04 in.) (0.05 in.) (0.10 in.)

izontal must not exceed the tolerances shown below.

6.6 Stamping Foil

Foil used for lettering or decorating a case hardbound book is tested to ensure the following standards are met.

Stamping foil shall be legible during the life of the binding and shall perform as follows, when tested in environmental conditions as described in Federal Test Method AA T CC 23-72:

Type of Exposure Time Minimum Requirement
70°C (158°F), Dry Heat 10 Days No change
70°C (158°F), Dry Heat 10 Days Moderate change
Oxygen 4 Days Very slight change
Ozone, 50 PPHM, 37.7°C (100°F) 4 Days No change
Hydrogen Sulfide Gas 2 Hours No change
Fade-Ometer 40 Hours Satisfactory
Oxides of Nitrogen 3 Cycles 3

(ANSI/NISO/LBI Z39.78-2000)