"Submit all Artwork in CMYK?" - utter nonsense!
Our very own CMP qualified Colour Management Master, Craig Hudson, explains why you should be wary of a wide format print house if they demand you send CMYK artwork files.
Does your wide format supplier request CMYK files? Ever wondered why? There really is no justification for the blanket application of a CMYK workflow in a wide format context. If you're needlessly converting your vibrant RGB photos and designs to CMYK before sending out to print you will be familiar with the deadening of colour this process can achieve! What a way to treat your vibrant design!
There are a few examples where converting all of your artwork to CMYK has a benefit, but in most instances, all it does is limit the colour available to you. In this piece, Craig explains why you should expect so much more of your wide format supplier.
“When most people think about colour numbers they think about mixing paint. “25% cyan mixed with 30% magenta and a splash of black…” They know it’s not that, but we all do it. It’s quite a useful image to get across a couple of very obvious points about colour communication so lets use it for a moment.
“Hi Jimmy, a customer wants us to print 25% cyan plus 30% magenta - pop over to the paint shop and grab a tin of each so we can mix them” “Ok.. but which make of paint? They’re all a bit different. If we use the wrong one, it won’t match” “They haven’t said - they’ve just said cyan and magenta. Any one of them will do won’t it?”
End result - a colour, in the right vicinity, and as accurate as was asked for - which was not very accurate!
The point: Sending CMYK (or RGB) files without specifying WHICH cmyk (or rgb) means inaccurate colour.
"I’ve converted it to CMYK because their printer prints in CMYK”
OK, so I've been a bit melodramatic. There's nothing wrong with CMYK colour spaces. Some CMYK spaces are pretty large, and won't kill your colour. Also, if you're trying to match prints produced via other methods, there's a valid argument for using a smaller CMYK colour space. But most of the time you see "submit in CMYK" the space isn't being specified. To work that way by default is a sad waste of colour.
Next time a printer asks you to submit in CMYK be sure to ask "which CMYK?" and if they pause before answering, run for the hills. You see, CMYK numbers alone only tell part of the story and won't lead to accurate colour reproduction. You need to specify the colour space you're in, and your printer needs to understand how to use that information to output colour on their machines. Don't worry if that seems complicated right now, the concept is straightforward and you don't need to be a colour scientist to grasp it.
There are three separate discussions here:
1) Why CMYK (or RGB) numbers alone are not enough - understanding what colour spaces are.
2) Why assuming the Adobe default SWOP colour space leads to the same boring colour everyone else has.
3) How you can make your colour POP with no extra effort!
So then…
CMYK (or RGB) numbers alone are not enough - a bit about colour spaces.
It maybe that "in the right ballpark" is good enough for your needs. If not, you need to define your required colour more accurately in the first place. You do that by defining the colour space you are working in. CMYK and RGB Colour Spaces are device dependant. That means, they refer to the range of colours a specific device is capable of producing. That range for colours is referred to as the "gamut" of the device in a given condition. Because every material and inkset is different, every product combination has its own unique gamut. There are also some special colour spaces - for example, US WebCoated SWOP v2. This is the default CMYK colour space of Adobe CS. If you don't tell Adobe CS to use a different CMYK space, this is the CMYK space you'll be working in by default. How is US Web Coated SWOP v2 a Device Dependant colour space if every one has it by default...? Well SWOP (Specifications Web Offset Publications) represents a specific set of inks, at specific densities, onto a specific paper stock. The principle is that offset printers "tune" their presses to meet this standard, so that there is consistency of output across presses. The key thing to understand about any colour space, CMYK or RGB, is that when you use the same numbers, either CMYK or RGB, in two different spaces, they represent two different colours. Without knowing the colour space, we don't know the colour the numbers are guiding us to. You do this by embedding the ICC profile, which tells the program opening the file, what colour space the file is in, and therefore what exact colour the numbers refer to.
2) Why assuming the SWOP colour space leads to the same boring colour everyone else has! The "Only Send Artwork in CMYK" idea stems from offset work, where presses are set up to output to the set standards (SWOP). Effectively all CMYK numbers are assumed to be in the SWOP colour space. Now, while Adobe still use SWOP as their default colour space, most of Europe are using FOGRA39 as the default, and indeed Hudson's will assume FOGRA39 as the colour space if nothing else is specified. So, what's wrong with that?
If you work in SWOP or FOGRA39 you’re limiting the colours in your artwork to the colours THOSE devices can print.
Your 100% colour values represent the limits of those devices. This is all you have. That's fine if you're sending work to print on a web offset printer because that’s all it can give you. There are times you might want this. If you want all your colours to match across different media on different printers you need to use the gamut of the device with least colour available. The others can limit to that. BUT there's a HUGE missed opportunity. Wide Format printers aren't restricted to SWOP or FOGRA. Most wide format media and ink combinations can achieve a much larger gamut. If you submit artwork in the smaller CMYK colour space you are unnecessarily restricting the colours in your artwork. There's nothing wrong with that, you'll get an accurate print of that limited colour artwork, but by submitting artwork like that you are effectively saying "ignore the bright punchy colours the inkjet machine is capable of or that were in my original design, I want you to limit the colours to those of a web offset printing press."
3) How to make use of that and achieve eye catching print… Build and send your artwork in a large RGB gamut. I recommend Adobe 1998 If you create artwork in AdobeRGB 1998 you can describe colours to (and beyond) the extremes of the printers capabilities. The only thing remaining is for us to determine what to do with the colours that you've specified that are outside the capabilities of the printer - and we're very comfortable with that process.
In Conclusion:
CMYK or RGB numbers do not tell anyone what exact colour is required without also knowing WHICH CMYK or RGB is being referred to. You can pass on this information by embedding the ICC profile within your file. You can also simply tell the person who has to open the file, and they can apply the correct profile at their computer.
Using a small CMYK colour space is fine, but it fails to utilise the full colour possibilities of wide format inkjet devices. (Note: If you were sending the artwork to both Litho and Wide Format Digital Printers and you wanted a close match, it would make sense to use SWOP - thus limiting the wide format machine to the gamut of the other device.)
By using a colour space such as Adobe RGB 1998 you can use colours designers working or providing artwork in a small CMYK space can't ask for. Your designs will shout where theirs merely whimper.
When a wide format printer asks you to submit in CMYK (and especially if they don't say WHICH CMYK) they're basically saying either "we don't know how to handle colours that we can't print" OR they're saying "we're playing it safe; we want a safe easy life where any print we do will match items printed on smaller gamut machines. Our clients will live with safe subdued prints." Using small CMYK spaces correctly it is a valuable tool in gaining consistent colour across different print methods. Using it by accident or default is a travesty!
The question is, are you happy to miss out on the bigger bang wide format printers can give you, or compromise your colour to accommodate a supplier's lack of knowledge or their desire of an easy life? If not, you do have a choice - find a supplier like Hudson's who welcome these discussions, and take your colour seriously!
Craig Hudson is the International PrePress Associations first qualified Colour Management Professional to achieve Master status, and the first UK based IPA qualified Colour Management Professional. Craig is Managing Director of Hudson Display Services Ltd, although he prefers the title "Chief Colour Wrangler" and may well have his business cards adjusted to match.