Quality standards

This document defines the general quality standards of the product manufactured at Sowa Sp. z o.o. printing house, as well as the acceptance criteria for the finished product.

1. COLORS

2. PRINTING

3. IMAGE FIT AND SPOT VARNISH LAYER

4. THERMOFOIL LAMINATION

5. CREASE

6. FORMAT

7. CUTTING PARALLELISM (for notebook binding)

8. CUTTING A SHEET INTO INDIVIDUAL USES (FINAL PRODUCT)

9. FOLDING/PERFORATION/GROOVING

10. BOOK SPINES

11. QUALITY OF SADDLE STITCH BINDING

12. QUALITY OF GLUED BINDING

13. QUALITY OF THREAD SEWN BINDING

14. QUALITY OF HARDCOVER BINDING

15. POSITION OF HOLES

16. IMAGE INCONSISTENCIES AND MECHANICAL INCONSISTENCIES

17. PACKAGING

18. INDIVIDUAL SHRINK WRAPPING

19. DELIVERY ACCEPTANCE CRITERIA

1. COLORS

ISO standards are the basic color guideline for digital prints, additional color guidelines may be provided by the customer in the form of digital proof or other color standard.
In the case of a reprint, the original print or also a proof accepted by the customer are the color standard.

Evaluation of color conformity is carried out visually as well as on the basis of color measurements made using a densitometer.
Acceptable - color deviates slightly from the standard.
Unacceptable - color deviates significantly from the standard.

Finishing processes may affect the color - the printing house is not responsible for color change resulting from finishing (e.g. lamination, varnishing) outside the printing machine.

2. PRINTING

Print image displacement on a page:

• Acceptable up to 0.5 mm
• Unacceptable greater than 0.5 mm.

3. IMAGE FIT AND SPOT VARNISH LAYER

An abnormal layer of offset, dispersion or UV varnish is considered to be one that has unvarnished areas greater than 2 mm2 (within the varnish area) on the surface to be varnished.
Varnish layer displacement in relation to the varnished image:
Acceptable up to 0.75 mm
Unacceptable greater than 0.75 mm.

4. THERMOFOIL LAMINATION

A correct lamination process is considered to be one that does not have any chipping or flaws on the laminated surface. Size of chips or flaws:
Acceptable: total area up to 1.5 mm2 or total length up to 5 mm
Unacceptable greater than 1.5 mm2 or length greater than 5 mm

Thermofoil lamination may stretch the image:
Acceptable up to 1.0 mm/500 mm
Unacceptable greater than 1.0 mm/500 mm..

5. CREASE

Deflection of the crease from the crease line:
Acceptable up to 1 mm
Unacceptable greater than 1 mm

6. FORMAT

The format of the notebook/book block is defined as the physical dimensions of the product specified in the Order. Format deviations are due to the natural variability of the process and should be within the acceptable tolerance range:
Acceptable deviation from the assumed format up to 1 mm
Unacceptable deviation from the assumed format greater than 1 mm.

7. CUTTING PARALLELISM (for notebook binding)

Acceptable parallelism deviation in the two edges of the binding measured after bending the notebook in half:
Acceptable up to 0.5mm/150mm cut
Unacceptable greater than 0.5mm/150mm cut.

8. CUTTING A SHEET INTO INDIVIDUAL USES (FINAL PRODUCT)

Acceptable deviations when cutting a sheet into individual uses:
Acceptable up to 1 mm.
Unacceptable greater than 1 mm.

9. FOLDING/PERFORATION/GROOVING

Folding - deviation in creases/perforation/grooving from the nominal line of its location (on each crease):
Acceptable up to 1 mm
Unacceptable greater than 1 mm

Attention!
Final deviations in creases/perforation/grooving are also impacted by acceptable deviations created during preceding technological processes, i.e. printing and sheet cutting.

10. BOOK SPINES

A compliant book spine is considered to be one that has dimensions in accordance with the parameters specified in the book cover file. Deviations:
Acceptable up to 1 mm
Unacceptable greater than 1 mm.

Position of the image on the spine in relation to the spine axis:
Acceptable displacement up to 0.5 mm horizontally and/or 1.0 mm vertically.
Unacceptable displacement greater than 0.5 mm horizontally or 1.0 mm vertically.

Displacement relative to the spine axis and skew may occur on cutaway spines or graphics and text on the spine:
Acceptable displacement up to 0.5 mm and/or skew up to 0.1 mm/100 mm
Unacceptable displacement greater than 0.5 mm and/or skew > 0.1 mm/100 mm.

11. QUALITY OF SADDLE STITCH BINDING

In a compliant saddle stitch binding the staples should not shift neither vertically nor horizontally.
Acceptable - horizontal displacement up to 0.75 mm, vertical displacement up to 2.5 mm
Unacceptable - horizontal displacement greater than 0.75 mm, vertical displacement greater than 2.5 mm

Additional sewing inconsistencies:
Staple clamp too tight - cuts the paper.
Staple clamp too loose - pages fall out.

12. QUALITY OF GLUED BINDING

A glued binding should have a compliant spine and side gluing.
The strength of the glued binding is checked as follows:

• the copy is grabbed by a selected single page and shook with moderate force
• the strength of the binding is considered compliant if the page is able to hold the weight of the entire copy when shaken

The shaking is repeated for several randomly selected pages, omitting the initial and final pages (due to side gluing).

13. QUALITY OF THREAD SEWN BINDING

As a standard, the thread sewing line should be placed evenly over the entire height of the book spine, and the ends of the stitch should end no closer than 10 mm from the expected cutting line. The number of stitches used depends on the height of the book.

Unacceptable sewing inconsistencies are:

• thread tension too loose - the spine "rounds" inward,
• thread tension too tight - the folds shift relative to each other,
• dangling thread of more than 15 mm after sewing the insert - uneven spine line after gluing the spine,
• thread holes too large - penetration of spine glue inside the insert.

The strength of thread sewing is considered compliant if one of the inner folds is able to hold the weight of the insert when shaken with moderate force.

14. QUALITY OF HARDCOVER BINDING

A hardcover book consists of a book block, which is subject to the same standards as a glue and sewn bound books, and a hardcover (cardboard facing covered with veneer), the quality parameters of which are specified below:

Acceptable:

• cover format deviation ≤ 1 mm,
• deviation in the position of the block in the cover ≤ 1 mm
• deviation in cardboard thickness ≤ 5 %
• deviation in the edge size ≤ 1 mm

Unacceptable:

• cover format deviation> 1 mm
• deviation in the position of the block in the cover > 1 mm
• deviation in cardboard thickness> 5 %
• deviation in the edge size > 1 mm

In the case of color embossing performed on structured materials, local undercoloring of the colored surface is permissible (depending on the covering material used). The porosity of the cover depends on the quality and degree of smoothing of the surface of the smoothed cardboard.

15. POSITION OF HOLES

The holes should not shift neither vertically nor horizontally. The functionality of being able to fit into a binder is the most critical for the position of the holes:
Acceptable displacement up to 1 mm
Unacceptable displacement greater than 1 mm.

16. IMAGE INCONSISTENCIES AND MECHANICAL INCONSISTENCIES

A product with image inconsistencies and mechanical inconsistencies that do not limit functionality is considered compliant. The presence and quantity of image and mechanical inconsistencies are determined visually. Typical image inconsistencies - spot, dot, line, paint transfer, dirt, image fading - unacceptable inconsistencies are greater than 2 mm2 in area or 5 mm in length (in total on a single page, not more than once per 150 pages of the publication). For covers, the tolerances are 1.5 mm2 in area or 3 mm in length, respectively.

17. PACKAGING

Packaging standards for softcover books:
Personal pick-up or delivery by the printing house's transport - products wrapped in bundles with paper or shrink wrap.
Pallet shipping - packages as above, stacked on a pallet, secured with pallet angles, wrapped in stretch film.
Parcel shipping - products shipped domestically wrapped in paper and three-layer cardboard, international shipments wrapped in paper and five-layer cardboard.

Hardcover books are packaged like international shipment.
Additional guidelines for packaging methods may be included in the customer's order.

18. INDIVIDUAL SHRINK WRAPPING

The strength of the seal is verified manually. The seal strength is considered compliant if both sealed edges support the weight of the entire bundle even when shaken with moderate force.

Additional unacceptable wrapping inconsistencies:

• mechanical damage to the copy
• rubbed film
• holes in the film
• lack of continuity of the seal (hole in the seal)

19. DELIVERY ACCEPTANCE CRITERIA

Delivery is considered to be in accordance with the order if at least 98% of the product has quality parameters within the tolerances allowed in this specification.
In the event of a shortage to the print run or a discovery of defective copies by the customer in the amount of no more than 2%, the claim of the print run will not be accepted, and the value of the defective/missing copies will be deducted from the invoice. In case of defects or shortage of more than 2%, the quantity will be reprinted and delivered. In the case of a shortage to the print run not exceeding 2%, the shortage will be reported to the customer before shipment, the invoice will be reduced by the resulting shortage.
Any remarks and objections, unless another written agreement is in force, should be submitted within 14 days from the date of delivery.