Colour
Guidelines
Spot
Colour
This is achieved by
using the four colour printing process (i.e. PMS colours must be broken down
into CMYK process).
Process
Colour
Colour specified in
percentages of cyan, magenta, yellow and black.
Dot
Gain
Dot
gain is not a fault of web offset printing, but rather a characteristic. The
dot gain can to some extent be accommodated in production but there are some
things, outlined below, that can help:
- All material should compensate
for dot gain of up to 15-20% in the 50% dot area. Ensure midtones are lighter
and have more contrast to compensate for the above dot gain.
- Highlights can also muddy if
there is a black dot visible, which will also gain on press. The first printing
highlights should be:
| |
C |
M |
Y |
K |
| First printing highlight |
3% |
2% |
2% |
0% |
| Midtones |
Allow for up to
15-20% dot gain |
| Shadow |
Range from 265-285% |
Under
Colour Removal
Under
Colour Removal (UCR) is a function which reduces the amount of cyan, magenta
and yellow in the neutral shadow areas and replaces them with black. This helps
minimize ink set-off and also improves contrast and shadow detail.
Correct settings on the scanner for the black tone curve is critical. A conventional
commercial separation program contains a full range black printer, affecting
the majority of the tonal range. In comparison, separations for Sunday Life
magazine should contain a short range black printer. For best results, the first
black dot should be introduced around the midtone region (50%) and gain tonally
towards the shadow stopping at 90%. A short range black is necessary to keep
important subject colours clean, vibrant and truer to the original.
We suggest using a skeleton black starting at 50% and ranging to 90% in the
shadow end.
Shadow areas in skin tones should use either cyan or black - not both. Magenta
and yellow in skin tones should be around 25-35% each.
The amount of shadowing should be kept to a minimum, especially with dark, muddy
or dirty colours that have a tendency to fill in on press.
Grey
Balance
Maintaining
Grey balance throughout the separation is extremely important for quality four-colour
reproduction.
Separations without neutral Grey's will reproduce with perceivable colour casts
on press. As a general rule for magazine reproduction, Grey balance requires
slightly more cyan relative to less amounts of magenta to yellow.
Four
Colour Mono Images
Four
colour mono images have a tendency to reproduce with colour and tonal shifts
and often the result differs to the original proof. We suggest using an achromatic,
or GCR, set-up. Increasing the use of black and reducing the other three colours
will result in a more neutral image that will reduce the risk of tonal and colour
shifts on press.
Total
Saturation
The
total saturation for process colour material should range from 265-285%. This
helps compensate for dot gain and allows for maximum shadow detail with minimum
ink set-off.
Saturation exceeding 285% will not result in darker shadows on magazine stock.
It simply leads to excessive set-off and causes shadow areas to plug; thus reducing
printed shadow detail.
Any single colour not intended to print solid should not exceed 80%.
We recommend that large areas of black be at least two colour (100% black, 60%
cyan) or four colours.
Colour
Correction
In
addition to addressing colour casts in an original, colour correction takes
on greater meaning in complimenting the inks and the stock used. Colour correction
should be utilized in all colour separations generated for magazine reproduction.
The main purpose of colour correction is to reduce the underlying colours that
tend to dirty the desired result on improved newsprint stock.
Significant improvement in reproduction quality can be obtained by keeping images
clean and bright through minimizing contaminated colours. For example, taking
yellow out of blues, magenta out of greens, cyan out of yellows and so on without
sacrificing detail to obtain clean colours, which significantly increases the
quality of the reproduction.
These colour techniques and recommendations will produce cleaner, brighter images
and can be applied to any kind of creative without the need to sacrifice mood.
Following these recommendations will provide the best opportunity of reproducing
colour on press.
Separation
Table
The
Magazine Separation Table located in the Downloads section of our web site is
not suitable for this product.
Typefaces
San
serif typefaces are the best choice for reproduction. They reproduce easily
with desired readability. Typefaces with thin or delicate serifs and strokes
should be avoided. Extremely fine strokes can drop out, while thick strokes
can plug on the press. Because of the ink and stock relationship, small type
tends to lose definition on the press.
Coloured type or solid backgrounds can print using a single colour at 100%.
Should a second or third colour be required, these extra colours should be
limited to 95%, keeping within the total ink limit of 285%. This will allow
the ink to trap on the press and result in a consistent and balanced printing.
For legibility reasons, consideration should be given when attempting to reproduce
type as a light screen tint. For best results, avoid screening type styles
with a fine to medium weight and those with serifs.
For optimum results it is suggested that type not overprint a background screen
(tint or ghosted image) greater than 30% visual density. This allows for dot
gain and provides necessary contrast between text matter and the background
image.
Typefaces
in Reverse
- Typefaces in four colours should
be sans serif and bold, no smaller than 12pt.
- Type with serifs or screens,
reversed out of a four colour image or colour, should be 12pt or greater
in size, otherwise the material will not be accepted. This allows for slight
variances in register while maximizing legibility.
- Any reverse type should be limited
to two colours maximum. For contrast and readability, reverse type should
not be positioned within screened areas less than 50%, or in yellow or other
light coloured backgrounds.
Line
Art
Minimum
width 0.125mm (0.005 inch) with a maximum of two colours overprinting.
Avoid line art less than 1 pt.
Disclaimer
Whilst internal production
processes may verify that material is within specifications the onus is firmly
on the tradehouse to supply material within specification. It is also a requirement
of our specifications that advertising material be delivered on time so quality
checking procedures can take place. Late material is liable to incur additional
production costs.
John Fairfax reserves the right to refuse any material that does not meet
the Fairfax specifications.