adobe cs — colour #03

adobe cs — colour #01 and colour #02 started an explication of the excruciating world of colour management. excruciating, not because it is immeasurably difficult, but because so many seem to avoid it altogether — this is unnecessary.

colour management can be extraordinarily complex if you get into the nitty gritty — but most of us don’t need to delve that deep. so, do yourself a favour and get a basic working knowledge of colour management to give your files the best chance once they hit the press.

unfortunately, there’s no definitive solution to the problem. no one can say “here are the settings to set and the buttons to push” because, well, it depends. let’s see why — here’s a pretty standard choice for colour settings in InDesign (under edit > color settings…):
screen grab of  North America General Purpose colour settings

now that’s probably fine if you’re a general purpose kind of person working in north america. but if you’re a prepress kind of person in australia it’s pretty shitty. one of the key rules of colour management is give yourself the widest practicable colour gamut as your starting point. hover your mouse over where it says “sRGB…” and you’ll see this description pop up at the bottom of the window :
screen grab of description for sRGB color space

see how InDesign gives you clues about what settings to use — “not recommended for prepress work (because of its limited color gamut)“. if you change to the north america prepess settings you’ll see the rgb profile change to adobe rgb (1998) — a better choice for prepress work, because it has a wider gamut which also, conveniently, more closely resembles the cmyk gamut — as its description explains :
screen grab of north america prepress colour settings

but for aussie prepress dudes, we’re still not there. swop stands for “Specifications for Web Offset Publications” (for those who don’t realise, “web” is the term for printing from a paper roll). in australia, most commercial printing (apart from newspapers, magazines and catalogues) is done through sheet offset.

in adobe cs — colour #01 we saw that swop restricts the total ink coverage to 300% with a maximum black of 90%. but sheet offset can tolerate more ink and this is exactly why aussies are often disappointed by flat images when their shit hits the press — they are restricting their images to an unnecessarily narrow gamut by using swop — which they do either because it’s the default or because it’s what is recommended on all the (mostly north american) forums.

a decent sheet offset press/operator under good conditions can handle a tic (or tac if you prefer) of about 350% so let’s look at some colour spaces whose descriptions match that :
screen grab of US sheetfed offset descriptionscreen grab of fogra27 descriptionscreen grab of fogra39 description

judging by the descriptions, these should all give similar results but, unfortunately, although InDesign did a good job of pointing us at a good rgb profile, it’s not quite so helpful when it comes to cmyk. remember, the image from colour #01 and colour #02 had a black background of r0g0b0. here’s how those three cmyk profiles will render that colour :
screen grab of separations preview panel from each of the three profiles

u.s.sc and fogra27 do indeed give us a tic of 350% — but look at the difference in the separations. that 85% total black is diabolical. you’re just about guaranteed to get shitty detail in your shadow areas using u.s.sc because it’s relying so heavily on all four plates to create the dark colours — whereas fogra27 loads as much achromatic data as possible onto the black plate which will almost certainly result in a crisper result.

looking at the data for fogra39 we can see that the description was incorrect — it only allows for a tic of 330% (not 350%) but we can probably put this down to a typo — it’s very likely the fogra39 description was just copied from fogra27, which has been with us for longer.

so, is fogra27 better than fogra39? again, it depends. as mentioned above, 350% tic is easily achievable under ideal conditions but very much of our printing is done in a subideal reality. if you’re a prepress dude in australia sending high quality work to an excellent printer who has plenty of time (and budget) to do a high quality job, fogra27 is a good choice. if you’re sending stuff to a decent printer who’s been screwed down on the delivery deadline, then fogra39 will give you and them less grief.

having said all that … in an ideal world we would always get to speak directly with the printer’s production dude for explicit instructions on the best protocol to use for each job — but this isn’t always possible or practical — so we have to get better at best-guess scenarios.


• related post : InDesign tip : #24 : checking the black plate in separations preview.
• related post : adobe cs — colour #01 : you don’t need to convert images to cmyk.
• related post : adobe cs — colour #02 : you really need to get your shit together.

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