Archant Colour Guide

COLOURSPACE, GAMUT & INK WEIGHT

COLOURSPACE

RGB

The colourspace where every colour represented is constructed by mixing varying percentages of Red, Green and Blue.  It is used in everyday applications such as computer monitors, digital cameras and scanners. It works because it is an illuminated source . . . i.e. it has light shining through it. It is not possible to reproduce colours mixed in RGB onto the printed page (no illuminated source being the fundamental downfall) we have to convert everything to . . .

 

CMYK

A colourspace where every colour represented is constructed by mixing varying percentages of Cyan, Magenta, Yellow and Key (Black to me and you).  The different percentages are achieved by printing different amounts of these colours by using randomly-placed dots on printing plates.  Of course, the CMYK printing process has limitations, and that is why a company  called Pantone came up with a reference system called . . .

 

PANTONE

Pantone colours are “Spot” colours and are made up from printing solid areas of ink.   Pantone colours are not used in newsprint publications. The make up of the Presses does not cater for anything other than the four process inks (CMYK).   However, most pre-Press graphic design programs  have Pantone to CMYK colour conversions that match – as close as possible – specified Pantone colours.   There is a newsprint alternative, it is . . .

 

FOCOLTONE

Archant’s own pre-Press and Design Studio departments uses, and recommends the use of, the Focoltone Colour System in all newsprint publications.   The complete Focoltone Colour System consists of 763 four-colour combinations of the  process colours, in single tints of all four inks from 5% to 85%.  The Focoltone system is supported in all commonly-used pre-Press programs . . . InDesign, QuarkXPress, Illustrator, Photoshop.

 

THE DIFFERENCES BETWEEN ON-SCREEN COLOURS  AND THE PRINTED COLOURS

Q Why does the image on my PC look different to the hard copy proof from my ink jet/laser printer which also looks different to the one in the newspaper?
A  No device in a publishing system is capable of reproducing the full range of colours viewable to the human eye. Each device operates within a specific colour space that can produce a certain range, or gamut, of colours.
A colour model determines the relationship between values, and the colour space defines the absolute meaning of those values as colours. Some colour models (such as CIE L*a*b) have a fixed colour space because they relate directly to the way humans perceive colour. These models are described as being device-independent. Other colour models (RGB, HSL, HSB, CMYK, and so forth) can have many different colour spaces. Because these models vary with each associated colour space or device, they are described as being device-dependent.
The three colour receptors in the human eye are Red, Green and Blue, PC monitors/TVs display in Red, Green and Blue. Red, Green, Blue (RGB) colours cannot be reproduced accurately when using Cyan, Magenta, Yellow and Black inks from the CMYK printing process. Because of these varying colour spaces, colours can shift in appearance as you transfer documents between different devices. Colour variations can result from differences in image sources; the way software applications define colour; print media (newsprint paper reproduces a smaller gamut than magazine-quality paper); and other natural variations, such as manufacturing differences in monitors or monitor age.

DON'T BE FOOLED BY SCREEN BRIGHTNESS

Our computer monitors, tablets, phones and camera LCDs are all backlit devices. They will always display our images brighter than any physical print. Be sure to correct for this, otherwise your prints may end up much darker than you expect.  To get an idea of how your advert will look in print, be sure to soft proof your advert to either ISOnewspaper 26v4 or ISO Coated v2 300% on a correctly calibrated screen to get an idea of how the advert will print.  It's always best to calibrate your screen using a colorimeter.  Two popular colorimeters on the market are the X-Rite i1 Display PRO and the Datacolor Spyder 4 Elite

How to install ICC profiles on your Windows computer
Right click on the ICC Profile once downloaded and select “Install Profile”.
Any applications (such as Adobe InDesign / Adobe Photoshop etc) that will use the profiles must be restarted to see the new profiles.

How to install ICC profiles on your computer - Apple / Mac
The ICC profile must be placed in the correct folder for your software to use them. (Macintosh HD > Library > Colorsync > Profiles)
Any applications (such as Adobe InDesign / Adobe Photoshop etc) that will use the profiles must be restarted to see the new profiles.

CONVERSION OF RGB TO CMYK

The easiest way to gain an understanding of the colour conversion process is to view this publication in both hard copy and online versions at the same time.  If you are reading this from the newsprint version please go online and, from the front page of Archant Publishing Services website (http://www.digitalnorfolk.com/production), you will find a link to the PageSuite RGB version of this colour guide.

If you are a graphic designer or page designer viewing the PageSuite RGB version and would like a hard copy version of this publication please email Archant Publishing Services Technical Manager Alan Doy at alan.doy@archant.co.uk with contact details.
If you are a prospective contract print customer viewing the PageSuite RGB version and would like a hard copy version of this publication please email Archant Print Sales Manager Ashley Barnes at ashley.barnes@archant.co.uk with contact details.
Wikipedia has some very good information at http://en.wikipedia.org/wiki/RGB_color_model and http://en.wikipedia.org/wiki/CMYK_color_model

 

RGB = ADDITIVE

The RGB colour model is an additive colour model in which Red, Green and Blue light are added together to reproduce a broad array of colours. The name of the model comes from the initials of the three additive primary colours, Red, Green, and Blue.

Equal values of Red, Green and Blue lightwaves = White.
Overlapping elements (secondary colours) are Cyan, Magenta and Yellow.

 

 

 

CMYK = SUBTRACTIVE

The CMYK model works by partially or entirely masking colours on a lighter, newsprint, background. The ink reduces the light that would otherwise be reflected. Such a model is called subtractive because inks “subtract” brightness from white.

Equal values of Cyan, Magenta and Yellow ink = Black.
Overlapping elements (secondary colours) are Red, Green and Blue.

DESTINATION SPACE

Convert all images to the correct icc profile (ISOnewspaper 26v4 or ISO Coated v2 300% (ECI), this will convert any RGB elements to the correct CMYK colour space and Ink weight.  Nb: If ink weight is in excess of 240% for newsprint and 300% for magazines, detail in any shadow areas will be lost as the paper becomes over saturated.

GAMUT

In colour reproduction either on computer monitors, desktop printers, newsprint presses or in photography, the gamut is a subset of colours. The most common usage refers to the subset of colours which can be accurately represented in a given circumstance, such as within a given colour space (i.e. RGB on a monitor or CMYK on a Press). Another sense, less frequently used but no less correct, refers to the complete set of colours found within an image at a given time. In this context, digitising a photograph, converting a digitised image to a different colour space, or outputting it to a given medium using a certain output device generally alters its gamut, in the sense that some of the colours in the original are lost in the process.

 

 

 

 

The representation of gamuts are sRGB to the left and CMYK for newsprint to the right.  In general terms . . . when using a digital camera or desktop scanner any images taken or scanned will, by default, be written away in sRGB colour mode (far left). When converted into CMYK images for use on newsprint the range of colours available is the smaller gamut (considerably smaller gamut) to the right.

Designers have the ability to check their colour gamut in any of the professional image editing programs (Photoshop CS3 screen shots below).  The image (below left) shows the selection of the red in the main window to be at top right. The “Warning Triangle” tells the designer the colour cannot be made in CMYK.  The image (below right) shows where the selection moves to – and the closest CMYK colour available – when the “Warning Triangle” is clicked.

Designers also have the ability to check their colour gamut in any image (Photoshop CS3 screen shot below). In reality most leave the conversion to the software.  The “Information” palette shown on top of the image of the tractor shows exclamation marks in the right hand CMYK info. This is where it’s out of gamut and cannot be converted exactly.

 

INK WEIGHT (TAC)

This is the area where most, if not all, colour issues stem from in newspaper printing. If a designer is manually colour correcting images for newsprint in Photoshop none of the default CMYK colour spaces use ISOnewsprint26v4.icc 240% Total Area Coverage (TAC) colour space.
The US Web (Coated) profile in early versions of Photoshop is, as it says in the name, for magazine work in the USA – a 300% TAC. FOGRA 39 in Photoshop CS6 in both General Purpose and Pre-Press CMYK settings is a 350% TAC magazine profile.

Download ISOnewsprint26v4.icc profile for newsprint
Download ISO Coated v2 300% (ECI).icc profile for magazine print

It is simply a matter of loading the .icc profile into Photoshop, etc. via Edit – Colour Settings – Working Spaces and letting the software handle the sRGB to CMYK conversion. The alternative is to follow a similar route to Archant Publishing Services in-house colour correction . . . use one of the many Automatic Image Processing solutions.

The above Contone Image is the CMYK result of processing the original sRGB off a Nikon Coolpix L810 Digital Still Camera (DSC) via Photoshop using the default colour settings of the program. Result is too much ink coverage within the image – 300% ink coverage instead of 240%. Below is same image with FOGRA 39 and 350% ink coverage.
The image to the left shows (in red) where there is too much ink.

Example of over ink weight images printing on Newspaper stock

Figure 1. This supplied image looks ok on screen and has been supplied in the CMYK colour space. The image has been colour corrected to the wrong icc print profile (U.S. Web Coated (SWOP) v2) and has an ink weight in excess of 340% because of this.  For reproduction on absorbent newspaper the ink weight is miles too high and the graphics designer should have used the icc profile ISOnewspaper 26v4 when correcting the image in Photoshop as this would have lowered the ink weight (TAC) to 240%.

Figure 2. This is how figure 1 has printed.  The over ink weight image has resulted in the dark areas of the image having excessive ink laid down on the press run and has caused the dark areas to lose detail and fill/bleed in, resulting in an image that is too dark with no detail in the shadows compared to the screen version (figure 1)

Figure 3. Has been supplied in the correct colour space (CMYK) and has been colour corrected to the correct icc profile (ISOnewspaper26v4) which has reduce the ink weight to 240%.  Figure 3 will print as intended and is much brighter in the darker areas with visible detail in the shadows.

Nb: For printing on newspaper, use the ISOnewspaper 26v4  icc profile which has a TAC (Total Area Coverage / Ink Weight) of 240%.  For printing on glossy magazine stock use ISO Coated v2 300% ECI  icc profile which has a TAC (Total Area Coverage / Ink Weight) of 300%. 

FONTS & TYPE

QUALITY OF IMAGES

RECOMMENDED COLOUR

TABLOID SIZES

MAGLOID & QUARTERFOLD SIZES