Quality levels for printing
On this page
- 1. Introduction
- 2. Guide to the categories
- 3. Detail requirements
- 4. General attributes
- 5. Evaluation methods
- 5.1 Solids (black)
- 5.2 Solids (colour)
- 5.3 Colour match
- 5.4 Ink gloss
- 5.5 Register
- 5.6 Hickies
- 5.7 Skew
- 5.8 Folding
- 5.9 Trim
- 5.10 Drilling
- 5.11 Halftone reproduction
- 5.12 Extraneous marks
- 5.13 Rub-resistance of printed image
- 5.14 Image positioning
- 5.15 Type print contrast signal (PCS), black type
- 5.16 Stroke width
- 5.17 Plugging
- 5.18 Doubling
- 5.19 Voids
1. Introduction
The Quality Levels for Printing was developed by Public Works and Government Services Canada (PSPC). It is the intent of this document to provide a means, common to both client and supplier, for specifying and measuring the quality requirements of finished printed work.
While this document relates to the final, printed work the quality of the components supplied to produce the work must be such as to support the requested print quality level. See A Customer Guide to Quality Printing for more information on supplying material for printing.
The quality levels in this document are rated in ascending order: Utility, Office, Informational, Library and Prestige. It is possible that attributes of a particular project can be specified at more than one quality level (i.e. folding tolerance - "Prestige", print quality - "Informational").
Utility and Office Quality is meant for documents which are primarily for internal or administrative use and appearance is not a high concern.
Informational Quality will cover the majority of Government publications. This quality level is the standard for producing a visually pleasing printed product using normal industry production practices. Typical jobs may range from single color line work to process color illustrations and will have an intended lifespan of less than ten years.
Library Quality is recommended if a publication has an intended lifespan of ten years or greater and is to be adhesive bound or case bound; The illustrations are functional to the use of the material (rather than purely decorative) and must be produced at an above average quality (e.g. professional journals); The overall quality characteristics are of above average importance and must be produced to a high quality level (e.g. internationally distributed publications).
Prestige Quality is recommended if the visual appearance has exceptional importance and small cosmetic defects are likely to result in adverse comments during its use (e.g. art reproductions) or the quality of the images, whether halftone, line work, or multicolor are vital to the usefulness of the publication; e.g. where halftone illustrations are critical in distinguishing subtle details of fauna or flora.
For the three higher quality levels, the same good production practices will assist in the achievement of the quality attributes but extra care and attention is critical in each succeeding higher level. This also means that the client must expect to pay more for a project at each higher quality level.
Please direct any comments or proposed revisions to:
Manager, Printing Procurement Division
Constitution Square
360 Albert St, 12th Floor
Ottawa ON K1A 0S5
613-998-0440
2. Guide to the categories
| Category | Synonyms | Typical of category |
|---|---|---|
| Prestige | Top quality |
|
| Library | Professional grade |
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| Informational | Commercial quality Publication grade |
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| Office | Stationery grade |
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| Utility | Basic quality Duplicator quality |
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3. Detail requirements
The test procedures are fully described in the "Evaluation Methods" section.
| Quality parameters and specifications | Prestige | Library | Informational | Office | Utility |
|---|---|---|---|---|---|
| Solids (black). Density by visual filter | |||||
| (a) Uncoated paper, average density must not be less than | 1.10 | 1.10 | 1.0 | 0.8 | 0.6 |
| (b) Coated paper, average density must not be less than | 1.30 | 1.30 | 1.20 | N/A | N/A |
| (c) Density range within a solid or between adjacent solids must not exceed | 0.05 | 0.10 | 0.10 | 0.15 | 0.20 |
| (d) Density variation throughout the run must not exceed | ± 0.05 | ± 0.10 | ± 0.10 | ± 0.15 | ± 0.25 |
| Solids (colour) test as directed | |||||
| Run variance shall not exceed | 0% | 0% | 2.5% | N/A | N/A |
| Colour match (single "spot" solour) test as directed | |||||
| The total colour difference (Delta E) between the specified and printed colour must not exceed | 2.0 | 3.0 | 4.0 | N/A | N/A |
| Ink gloss | |||||
| Minimum gloss (when specified) | 85% | 80% | 75% | N/A | N/A |
| Register | |||||
| Misregister shall not exceed | .05 mm(0.002 in.) | .075 mm(0.003 in.) | .100 mm(0.004 in.) | .250 mm(0.010 in.) | N/A |
| Hickies, spots and lint | |||||
| (a) Maximum permitted count in any one area | 1 | 5 | 15 | 25 | 55 |
| (b) Maximum average count per publication | 1 | 2 | 5 | 10 | 15 |
| Skewness of image | |||||
| Maximum displacement of image axis shall not exceed | .760 mm(0.030 in) | .760 mm(0.030 in.) | 1.50 mm(0.060 in.) | 3.20 mm(0.125 in.) | 6.40 mm(0.250 in.) |
| Folding - One, two or three folds | |||||
| Folds shall not be out of specified position by more than | .250 mm(± 0.010 in.) | .500 mm(± 0.020 in.) | .760 mm(±0.030in.) | 1.50 mm(± 0.60 in.) | 3.20 mm(±0.125 in.) |
| Folding - More than three folds. | |||||
| Folds shall not be out of specified position by more than | .760 mm(±0.030 in.) | .760 mm(±0.030 in.) | .760 mm(±0.030 in.) | 1.50 mm(±0.060 in.) | 3.20 mm(±0.125 in.) |
| Trim | |||||
| All work shall be trimmed to specified size | .250 mm(± 0.010 in.) | .500 mm(± 0.020 in.) | .760 mm(± 0.030 in.) | 1.50 mm(± 0.060 in.) | 3.20 mm(± 0.0125 in.) |
| Drilling | |||||
| All drilled holes shall be positioned as specified | .40 mm(± 0.015 in.) | .40 mm(± 0.015 in.) | .40 mm(± 0.015 in.) | .40 mm(± 0.015 in.) | .40 mm(± 0.015in. ) |
| Halftone reproduction | |||||
| The tone reproduction gradient must be within the specifted range of the ideal gradientHalftone Reproduction. The tone reproduction gradient must be within the specified range of the ideal gradient | ±10% | ±10% | ± 15% | ± 25% | N/A |
| Extraneous markings (scumming or set-off) | |||||
| Maximum acceptable background density (NB. extraneous lines, specks, scratches etc. will be assessed visually) | 0.02 | 0.03 | 0.0 | 0.06 | 0.010 |
| Image positioning | |||||
| All images shall be positioned as specified | .125 mm (± 0.005 in.) | .250 mm(± 0.010 in.) | .760 mm(± 0.030 in.) | 1.50 mm(± 0.060 in.) | 3.20 mm(± 0.125 in.) |
| The following parameters concern type matter | |||||
| Type print contrast signal (PCS), black Type | |||||
| (a) Uncoated paper, minimum acceptable PCS | 0.85 | 0.825 | 0.80 | 0.70 | 0.60 |
| (b) Coated paper, minimum acceptable PCS | 0.90 | 0.85 | 0.80 | N/A | N/A |
| (c) Maximum acceptable variation | ± 0.02 | ± 0.03 | ± 0.05 | ± 0.10 | ± 0.15 |
| Stroke width (percentage of original characters size) | |||||
| (a) Acceptable range of printed character size | 95% to 105% | 90% to 110% | 85% to 115% | 75% to 115% | 50% to 150% |
| (b) Maximum variation allowed | 5% | 5% | 5% | 10% | 15% |
| Plugging | |||||
| Maximum percent plugging allowable | 0% | 0% | 10% | 25% | 50% |
| Doubling and slur | |||||
| Maximum percent of doubling or slur allowable | 0% | 0% | 5% | 10% | 25% |
| Type voids (Broken type etc.) | |||||
| (a) Maximum permitted count in any one area | 2 | 2 | 5 | 15 | 50 |
| (b) Maximum average count per publication | 1 | 1 | 3 | 10 | 25 |
4. General attributes
4.1 Protective varnish or coating
Where applied, press varnish or coating shall prevent any rub-off of the printed image and if so specified the coated surface should have an even, high gloss finish.
4.2 Moiré
Halftone screens shall be angled so that no moiré effect is visible in the final print.
4.3 Drilling
All drilled holes shall be completely clear and not have torn edges.
4.4 Image graininess
In addition to the density specifications previously listed, halftones, solids and type shall not have a rough and grainy appearance.
4.5 Halftone mottle
Halftones shall not have a blotchy appearance such as caused by poor dot reproduction.
4.6 Covers and cover coatings
The covers of all publications shall be free of defects such as dog-eared corners, scuffs, scratches and dirt. Covers that have been plastic laminated shall have the laminate in contact with the cover material over 100% of the surface. The laminated cover shall be free of air bubbles and other defects and is to have a life expectancy equivalent to the intended life span of the book.
5. Evaluation methods
5.1 Solids (black)
With a equivalent reflection densitometer set on the visual filter, measure the density of solid printed areas throughout the publication job lot. Where solid areas are of substantial size, four measurements within the area shall be made and the measurements averaged to find the average density (X).
The density range shall be calculated by subtracting the minimum density from the maximum density measured within one solid area or in adjacent solids.
The average densities (X) are then averaged to find the overall average density (X). The difference between the overall average density and each individual average density is the density variation, which shall not exceed the specifications as listed in the detail requirements.
5.2 Solids (color)
With a reflection densitometer set on the correct densitometer filter, measure the density of solid printed color areas throughout the publication job lot.
The density run variation of any printed solid color shall not differ from the specified color by more than the tolerance levels listed in the detail requirements.
5.3 Color match
This test procedure is for use only with solid spot color and not for tints or process color. Measurements are made using a CIE response, three filters, and colorimeter with a D65 illuminate. Measurements are made on samples of the printed solid and on an approved color swatch. The measured results are expressed in CIE LAB coordinates: L*, a*, b*. The total color difference between the printed and specified color is calculated from the following formula:
delta E, or total color difference = squareroot of L2 + a2 + b2 where L, a and b are the measured differences between L*, a* and b* values for the actual and specified color samples.
NOTE: While the printer may not have the required equipment to make these measurements it is still possible to achieve an acceptable color match with the aid of a color reflection densitometer.
5.4 Ink gloss
The 75° gloss is measured by a gloss meter in accordance with TAPPI standard procedure T480-0S72.
5.5 Register
Misregister is recorded as the linear displacement of any color in any direction, relative to the other color.
5.6 Hickies
A representative area of print 10 cm x 10 cm square is selected. (Cutting a 10 cm x 10 cm Square from board, and placing the opening over the print to be tested conveniently do this.) The total number of hickies within this area is counted, and weighted according to the size of hicky as follows:
| table3 note *Size of hicky (approx.) | Weighting |
|---|---|
| Very small; 0.5 mm or less | 1 |
| Noticeable; 0.5 to 1 mm | 2 |
| Large; 1 to 3 mm | 3 |
| Very Large; 3 mm or greater | 6 |
| The total hicky rating is calculated as follows: | |
| (very small hickies) | x 1 |
| Plus (noticeable hickies) | x 2 |
| Plus (large hickies) | x 3 |
| Plus (very large hickies) | x 6 |
Table 3 Note
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NOTE: Approximate hicky size can be rapidly assessed, and with adequate accuracy, by means of a low-powered magnifying glass (5 to 10x) with measuring reticle.
5.7 Skew
Skew is the angular displacement of the image axis (horizontal or vertical) from its intended alignment. Draw a straight line that represents the actual axis of the printed image. With a line of type drawing a line along the base of the characters best does this. From one end of this line extend another line that is parallel to the intended axis or parallel to the top of the page. If any skew exists, these two lines will not be identical but will be displaced from each other. If this is the case, measure the linear displacement at a distance of 12 cm from where these two lines join. This displacement shall not exceed the specification.
5.8 Folding
Mispositioning of a fold is recorded as the linear displacement of actual from specified positioning, plus skews displacement (if any).
5.9 Trim
Long or short trim is recorded as the difference between specified and actual size of the trimmed work. A plus sign may be used to denote oversize work, and a minus sign for undersize.
5.10 Drilling
The mispositioning of a drilled hole is recorded as the linear displacement of the centre of the actual hole from the specified centre.
5.11 Halftone reproduction
(a) From a continuous-tone original
The criteria for acceptable halftone quality are a straight line when the tone reproduction curve is plotted on RIT Tone Reproduction graph paper, Type 2.
With the densitometer zeroed on the brightest highlight in the original, select several areas that represent the entire tonal range and measure the densities of these spots. Now, with the densitometer zeroed on an area of unprinted paper find the corresponding spots on the printed halftone and measure the densities. On the graph paper plot the densities from the original against the densities of the print. Draw the best straight line through these plotted points, which will represent the actual tone reproduction. Now draw another straight line from the highest plotted density point to the origin of the graph paper. This line represents the ideal tone reproduction. The gradient of the actual tone reproduction line shall not deviate from the gradient of the ideal tone reproduction line by more than the specified percentages.
(b) From supplied halftone film
The criteria and procedures are the same as in part (a), with one additional step. From the halftone film produce a positive non-glossy photographic contact print, which can then be measured in the same manner as the original in part (a).
5.12 Extraneous marks
Lines, spots, smears or other extraneous (background) markings are assessed visually. Generalized extraneous marking, covering a large area, (e.g. scumming, tinting) are assessed in terms of average reflection density of the affected area.
5.13 Rub-resistance of printed image
A representative sample of the print is placed on a Sutherland rub-tester (or equivalent instrument) and given 25 rubs at a pressure of 1 psi against an unmarked sample of stock similar to that on which the print is made. Density readings are then made on the rub-off smear, having pre-zeroed the densitometer on an unmarked sample of the rubbing stock. An average density is calculated for the rub-off smear.
5.14 Image positioning
Image displacement is recorded as the linear distance between specified and actual image positioning, where most of the press sheet is in register, but some is out of position.
5.15 Type print contrast signal (PCS), black Type
The type print contrast signal, i.e. density, is measured with a microdensitometer.
Measurements are made on type throughout the job lot and the average PCS is calculated. The PCS of any area shall not vary from the average PCS by more than the specified amounts.
5.16 Stroke width
The width of any part of a printed type character is measured and expressed as a percentage of the width of the same character on the original copy. The variation of stroke width is the difference between the maximum and minimum percentage values found on a page or sheet.
5.17 Plugging
This normally occurs with characters having an enclosed area such as the letters a, e and o. The degree of plugging is measured using a magnifier with a measuring reticle and expressed as the percentage of the open area that has been filled in.
5.18 Doubling
The secondary, or ghost, image adjacent to the primary character is measured with a magnifier having a measuring reticle and is expressed as a percentage of the primary image.
5.19 Voids
A representative area of printed type 8.5 cm wide by 10 lines deep is selected. The total number of voids within this area is counted and weighted according to the size of the void as follows:
| Size of void | Weighting |
|---|---|
| 0.002 to 0.004 in. | 1 |
| greater than 0.004 but less than 0.006 in. | 3 |
| 0.006 in. or greatertable4 note * | 10 |
Table 4 Note
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Multiply each void by its corresponding weighting factor and then sum the total count. The total void count as well as the average void count calculated from randomly chosen areas throughout the job should not exceed the specifications.
- Date modified:
- 2019-11-13