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4. Materials

This section outlines specifications for materials used in bookbinding.

4.1 Thread

Thread for sewing shall be cotton, nylon or cotton-covered polyester, of appropriate caliper to control swell. Tensile strength shall be no less than 1.54 kg (3.4 pounds) per linear inch for cotton, 1.81 kg (4 pounds) per linear inch for nylon and 1.91 kg (4.2 pounds) per linear inch for cotton-covered polyester.

The thread shall meet the following Canadian General Standards Board (CGSB) standards:

Nylon: Continuous Multifilament

4.2 Endpapers

The mechanical characteristics of endpapers shall meet or exceed the following specifications:

Test Performance TAPPI Test Number
Bursting Strength 18.1 kg per 2.5 em2 TAPPI T-403
(Mullen) (40 lbs.lin. Z)  
Folding Endurance
(MIT), with grain
275 double folds TAPPI T-511
Tear Resistance
(Elmendorf), with grain
114 grams TAPPI T-414

Unless otherwise specified, the two-part endpapers shall consist of No. 1 Offset, 200 M (Basis 25 in. x 38 in.), 148 gm2.

4.3 Adhesive

The adhesive used for any binding process shall be capable of forming a permanent bond between the surfaces to be joined, without the formation of air bubbles. The cohesion shall be such that the bonded materials will be damaged if separated.

Any adhesive used shall have a low pH value and long-term aging characteristics.

The adhesive used for casing-in shall be compatible with the adhesive used to make the case, so that the case adheres tightly and securely to the book block.

Adhesion of the covering material to the inlay and the endpapers in the joint is critical.

Glued surfaces must meet the test requirements as outlined in Section 5 on the Next Page herein.

4.4 Stitching Wire

Thickness: The thickness of the wire shall be measured and shall conform to the following specifications.

Breaking Load: When tested on an Instrom Tensile Tester (or equivalent instrument), the breaking load of the stitching wire shall conform to the following specifications:

Size Thickness Breaking Load Stretch
(ASWO) (mm) (Newtons) (%)
20 0.890 ± 0.02 493 ± 25 4 maximum
21 0.810 ± 0.02 436 ± 25 4 maximum
23 0.660 ± 0.02 347 ± 20 4 maximum
25 0.510 ± 0.02 223 ± 15 4 maximum
26 0.450 ± 0.02 142 ± 10 4 maximum
20-25 0.890 ± 0.02- 383 ± 20 4 maximum
  0.510 ± 0.02   4 maximum
20-23 0.890 ± 0.02-   4 maximum
  0.660 ± 0.02    

Stretch: When tested on an Instrom Tensile Tester (or equivalent instrument), the stretch or elongation of the stitching wire shall not exceed the limits shown above.

Flexibility: (Coated Wire) Lengths of stitching wire (20 cm) wound around a 5 mm diameter steel rod shall show no evidence of peeling or cracking of the coating from the substrate.

No coating failure
Coating failure

Corrosion Resistance: Five 10 cm lengths of stitching wire placed in 225 mL of water and observed at 24, 48 and 72 hours shall conform to the following requirements:

No rusting after 72 hours
No rusting after 48 hours but some rusting after 72 hours
Major Defect
Rusting after 24 hours
Critical Defect

4.5 Backlining Material

The back lining material shall consist of dirt-free cleaned cotton or mull; it may be napped on one side. It will weigh not less than 113 g per 0.9 m² (4 ounces/yd.²), plain weave, and single ply yarn.

The breaking strength by the strip method shall be 19 kg per 2.5 cm2 (42Ibs/in.2) for the warp and 24.5 kg per 2.5 cm2 (54Ibs/in.) for the filling.

4.5.1. Sewn Books

When the sewn book is 1.25 cm (1/2 in.) thick and less, the thread count of the backlining material shall not be less than 33 per 2.5 cm (1 in.) in the warp and 25 in the filling.

For sewn books thicker than 1.25 cm (1/2 in.), the thread count shall not be less than 45 per 2.5 cm (1 in.) in the warp and 38 in the filling.

4.6 Lining Paper

Lining paper shall have a basis weight of 120 M (Basis 25 in. x 38 in.), 90g/m², with a pH between 6 and 8. (Test method: Pulp and Paper Technical Association of Canada (PAPTAC) G-25P).

4.7 Headbands

Headbands shall be made of strips of cotton cloth about 1.58 cm (5/8 in.) wide with a rolled edge.

They may be a solid color or colored threads with a pattern of stripes or checks.

Headbands shall be securely attached to the head and tail of the spine of the book block, under the backlining material.

Headbands shall be color coordinated to the cover material.

4.8 Binder’s Board

Solid binder’s board or pasted chipboard shall be used as cover boards, as specified in the purchasing contract.

4.8.1 Caliper

The thickness of the board shall be adapted to the size and weight of the volume and shall be between 0.15 cm and 0.32 cm (0.060 in. and 0.125 in.).

4.8.2 pH

The pH level shall be between 6 and 8, according to the PAPTAC G-25P.

4.8.3 Surface

The board surface shall be free from lumps, indentations and mechanical imperfections. It shall be smooth and even.

4.8.4 Trimming

The board shall be trimmed square on all four sides and all edges shall be trimmed smooth.

4.8.5 Curl

The results of a curl test of the boards shall be within the requirements outlined in Section 5 on the Next Page.

4.9 Inlay

The inlay shall be of flexible boards and on the grain shall run parallel to the binding edge.

Inlays shall be not less than 0.30 mm (0.012 in.) thick and no more than 0.76 mm (0.030 in.) thick.

The inlay shall have a pH level of 6 to 8.

4.10 Cover Material

The cover material shall be as specified in the contract.

4.11 Cord

The cord used to line the cover material in the fold at the head and tail of the spine shall have a minimum basis weight of 3,560 g/m².

It may be made of any of the following materials:

  • Cotton, polyester or nylon with a multi-filamented type of construction;
  • Kraft paper with a single-filament twist type of construction. The kraft paper used shall have a pH value of 6 to 8. (PAPTAC Test method G25P.)

4.12 Lettering

Stamping foil: Stamping foil shall meet the requirements and tests outlined in Section 7.

Preprinted Covers: Preprinted covers shall be legible during the life of the binding, and shall adhere to the applicable quality levels for printing.

4.13 Reinforcing Material

The reinforcing cloth used for endpapers and tipping-in shall have no less than 77 warp threads per 2.5 cm (1 in.) and not less than 72 filling threads per 2.5 cm (1 in.)

The tensile strength (Strip Method) of the warp threads shall be no less than 20.4 kg per 2.5 cm (45 pounds per linear inch) and of the filling threads no less than 9 kg per 2.5 cm (20 pounds per linear inch).